IgM-Immunofluorescence Test as a Diagnostic Tool for Epidemiologic Studies of Schistosomiasis in Low Endemic Areas

The high sensitivity and the ability to diagnose schistosomiasis in a very early phase after infection have indicated the detection of IgM antibodies to Schistosoma mansoni gut antigens by the immunofluorescence test (IgM-IFT) as a useful serological test for epidemiological studies in low endemic areas. When applied in a follow-up study for two years, higher rates of seroconversion from IFT negative to positive were observed during the summer months, suggesting seasonal transmission of schistosomiasis in the rural area of the municipality of Itariri (São Paulo, Brazil). In each survey, blood samples from about 600 schoolchildren were collected on filter paper and submitted to IgM-IFT. When the blood samples were classified for the IgM antibody levels, according to the intensity of fluorescent reaction observed at fluorescence microscopy, and correlated to the egg counts in the Kato-Katz positive patients, no association was observed. This observation might suggest that the intensity of fluorescence observed in the IgM-IFT, as an indicator of IgM antibody levels, could not be an useful seroepidemiological marker for classifying areas of low endemicity according to degrees of infection.

Long-term transcutaneous monitoring of oxygen tension and carbon dioxide at 42 degrees C in critically ill neonates: improved performance of the tcpo2 monitor with topical metabolic inhibition.

Whereas during the last few years handling of the transcutaneous PO2 (tcPO2) and PCO2 (tcPCO2) sensor has been simplified, the high electrode temperature and the short application time remain major drawbacks. In order to determine whether the application of a topical metabolic inhibitor allows reliable measurement at a sensor temperature of 42 degrees C for a period of up to 12 h, we performed a prospective, open, nonrandomized study in a sequential sample of 20 critically ill neonates. A total of 120 comparisons (six repeated measurements per patient) between arterial and transcutaneous values were obtained. Transcutaneous values were measured with a control sensor at 44 degrees C (conventional contact medium, average application time 3 h) and a test sensor at 42 degrees C (Eugenol solution, average application time 8 h). Comparison of tcPO2 and PaO2 at 42 degrees C (Eugenol solution) showed a mean difference of +0.16 kPa (range +1.60 to -2.00 kPa), limits of agreement +1.88 and -1.56 kPa. Comparison of tcPO2 and PaO2 at 44 degrees C (control sensor) revealed a mean difference of +0.02 kPa (range +2.60 to -1.90 kPa), limits of agreement +2.12 and -2.08 kPa. Comparison of tcPCO2 and PaCO2 at 42 degrees C (Eugenol solution) showed a mean difference of +0.91 (range +2.30 to +0.10 kPa), limits of agreement +2.24 and -0.42 kPa. Comparison of tcPCO2 and PaCO2 at 44 degrees C (control sensor) revealed a mean difference of +0.63 kPa (range 1.50 to -0.30 kPa), limits of agreement +1.73 and -0.47 kPa. CONCLUSION: Our results show that the use of an Eugenol solution allows reliable measurement of tcPO2 at a heating temperature of 42 degrees C; the application time can be prolongued up to a maximum of 12 h without aggravating the skin lesions. The performance of the tcPCO2 monitor was slightly worse at 42 degrees C than at 44 degrees C suggesting that for the Eugenol solution the metabolic offset should be corrected.

Chronic delivery of antibody fragments using immunoisolated cell implants as a passive vaccination tool.

BACKGROUND: Monoclonal antibodies and antibody fragments are powerful biotherapeutics for various debilitating diseases. However, high production costs, functional limitations such as inadequate pharmacokinetics and tissue accessibility are the current principal disadvantages for broadening their use in clinic. METHODOLOGY AND PRINCIPAL FINDINGS: We report a novel method for the long-term delivery of antibody fragments. We designed an allogenous immunoisolated implant consisting of polymer encapsulated myoblasts engineered to chronically release scFv antibodies targeted against the N-terminus of the Aβ peptide. Following a 6-month intracerebral therapy we observed a significant reduction of the production and aggregation of the Aβ peptide in the APP23 transgenic mouse model of Alzheimer's disease. In addition, functional assessment showed prevention of behavioral deficits related to anxiety and memory traits. CONCLUSIONS AND SIGNIFICANCE: The chronic local release of antibodies using immunoisolated polymer cell implants represents an alternative passive vaccination strategy in Alzheimer's disease. This novel technique could potentially benefit other diseases presently treated by local and systemic antibody administration.

Carbon isotopic ratio analysis by gas chromatography/combustion/isotope ratio mass spectrometry for the detection of gamma-hydroxybutyric acid (GHB) administration to humans.

Since GHB (gamma-hydroxybutyric acid) is naturally produced in the human body, clinical and forensic toxicologists must be able to discriminate between endogenous levels and a concentration resulting from exposure. To suggest an alternative to the use of interpretative concentration cut-offs, the detection of exogenous GHB in urine specimens was investigated by means of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). GHB was isolated from urinary matrix by successive purification on Oasis MCX and Bond Elute SAX solid-phase extraction (SPE) cartridges prior to high-performance liquid chromatography (HPLC) fractioning using an Atlantis dC18 column eluted with a mixture of formic acid and methanol. Subsequent intramolecular esterification of GHB leading to the formation of gamma-butyrolactone (GBL) was carried out to avoid introduction of additional carbon atoms for carbon isotopic ratio analysis. A precision of 0.3 per thousand was determined using this IRMS method for samples at GHB concentrations of 10 mg/L. The (13)C/(12)C ratios of GHB in samples of subjects exposed to the drug ranged from -32.1 to -42.1 per thousand, whereas the results obtained for samples containing GHB of endogenous origin at concentration levels less than 10 mg/L were in the range -23.5 to -27.0 per thousand. Therefore, these preliminary results show that a possible discrimination between endogenous and exogenous GHB can be made using carbon isotopic ratio analyses.

Transfer factor for carbon monoxide: a glance behind the scene.

The transfer factor for carbon monoxide (TLCO) is widely used in pulmonary function laboratories because it represents a unique non-invasive window on pulmonary microcirculation. The TLCO is the product of two primary measurements, the alveolar volume (VA) and the CO transfer coefficient (KCO). This test is most informative when VA and KCO are examined, together with their product TLCO. In a normal lung, a low VA due to incomplete expansion is associated with an elevated KCO, resulting in a mildly reduced TLCO. Thus, in case of low VA, a seemingly "normal KCO" must be interpreted as an abnormal gas transfer. The most common clinical conditions associated with an abnormal TLCO are characterised by a limited number of patterns for VA and KCO: incomplete lung expansion, discrete loss of alveolar units, diffuse loss of alveolar units, emphysema, pulmonary vascular disorders, high pulmonary blood volume, alveolar haemorrhage.

The second internal transcribed spacer of nuclear ribosomal DNA as a tool for Latin American anopheline taxonomy: a critical review

Among the molecular markers commonly used for mosquito taxonomy, the internal transcribed spacer 2 (ITS2) of the ribosomal DNA is useful for distinguishing among closely-related species. Here we review 178 GenBank accession numbers matching ITS2 sequences of Latin American anophelines. Among those, we found 105 unique sequences corresponding to 35 species. Overall the ITS2 sequences distinguish anopheline species, however, information on intraspecific and geographic variations is scarce. Intraspecific variations ranged from 0.2% to 19% and our analysis indicates that misidentification and/or sequencing errors could be responsible for some of the high values of divergence. Research in Latin American malaria vector taxonomy profited from molecular data provided by single or few field capture mosquitoes. However we propose that caution should be taken and minimum requirements considered in the design of additional studies. Future studies in this field should consider that: (1) voucher specimens, assigned to the DNA sequences, need to be deposited in collections, (2) intraspecific variations should be thoroughly evaluated, (3) ITS2 and other molecular markers, considered as a group, will provide more reliable information, (4) biological data about vector populations are missing and should be prioritized, (5) the molecular markers are most powerful when coupled with traditional taxonomic tools.

High-density electric source imaging (esi) in focal epilepsy: a prospective study of 150 operated patients

Purpose: EEG is mandatory in the diagnosis of the epilepsy syndrome. However, its potential as imaging tool is still under estimated. In the present study, we aim to determine the prerequisites of maximal benefit of electric source imaging (ESI) to localize the irritative zone in patients with focal epilepsy. Methods: One hundred fifty patients suffering from focal epilepsy and with minimum 1 year postoperative follow-up were studied prospectively and blinded to the underlying diagnosis. We evaluated the influence of two important factors on sensitivity and specificity of ESI: the number of electrodes (low resolution, LR-ESI: <30 versus high resolution, HR-ESI: 128-256 electrodes), and the use of individual MRI (i-MRI) versus template MRI (t-MRI) as the head model. Findings: ESI had a sensitivity of 85% and a specificity of 87% when HR-ESI with i-MRI was used. Using LR-ESI, sensitivity decreased to 68%, or even 57% when only t-MRI was available. The sensitivity of HR-ESI/i-MRI compared favorably with those of MRI (76%), PET (69%) and ictal/interictal SPECT (64%). Interpretation: This study on a large patient group shows excellent sensitivity and specificity of ESI if 128 EEG channels or more are used for ESI and if the results are coregistered to the patient's individual MRI. Localization precision is as high as or even higher than established brain imagery techniques. HR-ESI appears to be a valuable additional imaging tool, given that larger electrode arrays are easily and rapidly applied with modern EEG equipment and that structural MRI is nearly always available for these patients.

Carbon isotope excursions and microfacies changes in marine Permian-Triassic boundary sections in Hungary

Several Permian-Triassic boundary sections occur in various structural units within Hungary. These sections represent different facies zones of the western Palaeotethys margin. The Gardony core in the NE part of the Transdanubian Range typically represents the inner ramp, while the Balvany section in the Bukk Mountains of northern Hungary represents an outer ramp setting. The two sections have different patterns for their delta(13)C values. The Balvany section shows a continuous change towards more negative delta(13)C values starting at the first biotic decline, followed by a sharp, quasi-symmetric negative peak at the second decline. The appearance of the delta(13)C peak has no relationship to the lithology and occurs within a shale with low overall carbonate content, indicating that the peak is not related to diagenesis or other secondary influences. Instead, the shift and the peak reflect primary processes related to changes in environmental conditions. The continuous shift in delta(13)C values is most probably related to a decrease in bioproductivity, whereas the sharp peak can be attributed to an addition of C strongly depleted in (13)C to the ocean-atmosphere system. The most plausible model is a massive release of methane-hydrate. The quasi-symmetric pattern suggests a rapid warming-cooling cycle or physical unroofing of sediments through slope-failure and releasing methane-hydrate. The Gidony-1 core shows a continuous negative delta(13)C shift starting below the P-T boundary. However, the detailed analyses revealed a sharp delta(13)C peak in the boundary interval, just below the major biotic decline, although its magnitude doesn't reach that observed in the Balvany section. Based on careful textural examination and high-resolution stable isotope microanalyses we suggest that the suppression of the delta(13)C peak that is common in the oolitic boundary sections is due to combined effects of condensed sedimentation, sediment reworking and erosion, as well as perhaps diagenesis. (c) 2005 Elsevier B.V All rights reserved.

Reliability of stable carbon and oxygen isotope compositions of pedogenic needle fibre calcite as environmental indicators: examples from Western Europe.

Stable carbon and oxygen isotope analyses were conducted on pedogenic needle fibre calcite (NFC) from seven sites in areas with roughly similar temperate climates in Western Europe, including the Swiss Jura Mountains, eastern and southern France, northern Wales, and north-eastern Spain. The δ(13)C values (-12.5 to-6.8 0/00 Vienna Pee Dee Belemnite (VPDB)) record the predominant C(3) vegetation cover at the sites. A good correlation was found between mean monthly climatic parameters (air temperature, number of frost days, humidity, and precipitation) and δ(18)O values (-7.8 to-3.40/00 VPDB) of all the NFC. Similar seasonal variations of δ(18)O values for monthly NFC samples from the Swiss sites and those of mean monthly δ(18)O values of local precipitation and meteorological data point out precipitation and preferential growth/or recrystallisation of the pedogenic needle calcite during dry seasons. These covariations indicate the potential of stable isotope compositions of preserved NFC in fossil soil horizons as a promising tool for palaeoenvironmental reconstructions.

Evaluation of the new advanced 15-loci MIRU-VNTR genotyping tool in Mycobacterium tuberculosis molecular epidemiology studies

Background. During the last few years, PCR-based methods have been developed to simplify and reduce the time required for genotyping Mycobacterium tuberculosis (MTB) by standard approaches based on IS6110-Restriction Fragment Length Polymorphism (RFLP). Of these, MIRU-12-VNTR (Mycobacterial interspersed repetitive units- variable number of tandem repeats) (MIRU-12) has been considered a good alternative. Nevertheless, some limitations and discrepancies with RFLP, which are minimized if the technique is complemented with spoligotyping, have been found. Recently, a new version of MIRU-VNTR targeting 15 loci (MIRU-15) has been proposed to improve the MIRU-12 format. Results. We evaluated the new MIRU-15 tool in two different samples. First, we analyzed the same convenience sample that had been used to evaluate MIRU-12 in a previous study, and the new 15-loci version offered higher discriminatory power (Hunter-Gaston discriminatory index [HGDI]: 0.995 vs 0.978; 34.4% of clustered cases vs 57.5%) and better correlation (full or high correlation with RFLP for 82% of the clusters vs 47%). Second, we evaluated MIRU-15 on a population-based sample and, once again, good correlation with the RFLP clustering data was observed (for 83% of the RFLP clusters). To understand the meaning of the discrepancies still found between MIRU-15 and RFLP, we analyzed the epidemiological data for the clustered patients. In most cases, splitting of RFLP-clustered patients by MIRU-15 occurred for those without epidemiological links, and RFLP-clustered patients with epidemiological links were also clustered by MIRU-15, suggesting a good epidemiological background for clustering defined by MIRU-15. Conclusion. The data obtained by MIRU-15 suggest that the new design is very efficient at assigning clusters confirmed by epidemiological data. If we add this to the speed with which it provides results, MIRU-15 could be considered a suitable tool for real-time genotyping.

Microbiological activities in moonmilk monitored using isothermal microcalorimetry (cave of Vers Chez le Brandt, Neuchatel, Switzerland)

Studies of the influence of microbial communities on calcium carbonate deposits mostly rely on classical or molecular microbiology, isotopic analyses, and microscopy. Using these techniques, it is difficult to infer microbial activities in such deposits. In this context, we used isothermal microcalorimetry, a sensitive and nondestructive tool, to measure microbial activities associated with moonmilk ex-situ. Upon the addition of diluted LB medium and other carbon sources to fresh moonmilk samples, we estimated the number of colony forming units per gram of moonmilk to be 4.8 3 105 6 0.2 3 105. This number was close to the classical plate counts, but one cannot assume that all active cells producing metabolic heat were culturable. Using a similar approach, we estimated the overall growth rate and generation time of the microbial community associated with the moonmilk upon addition of various carbon sources. The range of apparent growth rates of the chemoheterotrophic microbial community observed was between 0.025 and 0.067 h21 and generation times were between 10 and 27 hours. The highest growth rates were observed for citrate and diluted LB medium, while the highest carbon-source consumption rates were observed for low molecular weight organic acids (oxalate and acetate) and glycerol. Considering the rapid degradation of organic acids, glucose, and other carbon sources observed in the moonmilk, it is obvious that upon addition of nutrients during snow melting or rainfall these communities can have high overall activities comparable to those observed in some soils. Such communities can influence the physico-chemical conditions and participate directly or indirectly to the formation of moonmilk.

Validation of a new tool to assess health-related quality of life in psoriasis: the PSO-LIFE questionnaire.

BACKGROUND Several questionnaires have been used to measure health related quality of life (HRQoL) in patients with psoriasis, few have been adapted for use in Spain; none of them was developed specifically for the Spanish population. The purpose of the study was to validate and assess the sensitivity to change of a new questionnaire to measure HRQOL in patients with psoriasis (PSO-LIFE). METHODS Observational, prospective, multicenter study performed in centers around Spain. Patients with active or inactive psoriasis completed the PSO-LIFE together with other Dermatology Quality of Life Index (DLQI) and Psoriasis Disability Index (PDI). A control group of patients with urticaria or atopic dermatitis was also included. Internal consistency and test-retest reliability of the PSO-LIFE were assessed by calculating Cronbach's alpha and Intraclass Correlation Coefficient (ICC). Validity was assessed by examining factorial structure, the capacity to discriminate between groups, and correlations with other measures. Sensitivity to change was measured using effect sizes. RESULTS The final sample included for analysis consisted of 304 patients and 56 controls. Mean (SD) age of psoriasis patients was 45.3 (14.5) years compared to 38.8 (14) years for controls (p < 0.01). Cronbach's alpha for the PSO-LIFE was 0.95 and test-retest reliability using the ICC was 0.98. Factor analysis showed the questionnaire to be unidimensional. Mean (SD) PSO-LIFE scores differed between patients with psoriasis and controls (64.9 [22.5] vs 69.4 [17.3]; p < 0.05), between those with active and inactive disease (57.4 [20.4] vs 76.4 [20.6]; p < 0.01), and between those with visible and non-visible lesions (63.0 [21.9] vs. 74.8 [23.9]; p < 0.01). The correlation between PSO-LIFE and PASI scores was moderate (r = -0.43) while correlations with DLQI and PDI dimensions ranged from moderate to high (between 0.4 and 0.8). Effect size on the PSO-LIFE in patients reporting 'much improved' health status at study completion was 1.01 (large effect size). CONCLUSIONS The present results provide substantial support for the reliability, validity, and responsiveness of the PSO-LIFE questionnaire in the population for which it was designed.

Carbon dioxide baited trap catches do not correlate with human landing collections of Anopheles aquasalis in Suriname

Three types of carbon dioxide-baited traps, i.e., the Centers for Disease Control Miniature Light Trap without light, the BioGents (BG) Sentinel Mosquito Trap (BG-Sentinel) and the Mosquito Magnet® Liberty Plus were compared with human landing collections in their efficiency in collecting Anopheles (Nyssorhynchus) aquasalis mosquitoes. Of 13,549 total mosquitoes collected, 1,019 (7.52%) were An. aquasalis. Large numbers of Culex spp were also collected, in particular with the (BG-Sentinel). The majority of An. aquasalis (83.8%) were collected by the human landing collection (HLC). None of the trap catches correlated with HLC in the number of An. aquasalis captured over time. The high efficiency of the HLC method indicates that this malaria vector was anthropophilic at this site, especially as carbon dioxide was insufficiently attractive as stand-alone bait. Traps using carbon dioxide in combination with human odorants may provide better results.

High prevalence and lack of diversity of Wolbachia pipientis in Aedes albopictus populations from Northeast Brazil

The use of Wolbachia as a tool to control insect vectors has recently been suggested. In this context, studies on the prevalence and diversity of this bacterium in wild populations are relevant. Here, we evaluated the diversity of two Wolbachiagenes (ftsZ and wsp) and the prevalence of this endosymbiont in wild Aedes albopictus. Using semi-nested polymerase chain reaction, our results showed that 99.3% of the individuals were superinfected with Wolbachia. In regards to genetic diversity, the two genes showed no variation within or among mosquito populations. An analysis of other Wolbachia markers may help to clarify the relationship between insect and endosymbiont.

Middle and Late Jurassic carbon stable-isotope stratigraphy and radiolarite sedimentation of the Umbria-Marche basin (Central Italy)

A continuous carbon isotope curve from Middle-Upper Jurassic pelagic carbonate rocks was acquired from two sections in the southern part of the Umbria-Marche Apennines in central Italy. At the Colle Bertone section (Terni) and the Terminilletto section (Rieti), the Upper Toarcian to Bajocian Calcari e Marne a Posidonia Formation and the Aalenian to Kimmeridgian Calcari e Marne a Posidonia and Calcari Diasprigni formations were sampled, respectively. Biostratigraphy in both sections is based on rich assemblages of calcareous nannofossils and radiolarians, as well as some ammonites found in the upper Toarcian-Bajocian interval. Both sections revealed a relative minimum of delta(13)C(PDB) close to + 2 parts per thousand in the Aalenian and a maximum around 3.5 parts per thousand in early Bajocian, associated with an increase in visible chert. In basinal sections in Umbria-Marche, this interval includes the very cherry base of the Calcari Diasprigni Formation (e.g. at Valdorbia) or the chert-rich uppermost portion of the Calcari a Posidonia (e.g at Bosso). In the Terminilletto section, the Bajocian-early Barthonian interval shows a gradual decrease in delta(13)C(PDB) values and a low around 2.3 parts per thousand. This part of the section is characterised by more than 40 m of almost chart-free limestones and correlates with a recurrence of limestone-rich facies in basinal sections at Valdorbia. A double peak with values of delta(13)C(PDB) around + 3 parts per thousand was observed in the Callovian and Oxfordian, constrained by well preserved radiolarian faunas. The maxima lie in the Callovian and the middle Oxfordian, and the minimum between the two peaks should be near the Callovian/Oxfordian boundary. In the Terminilletto section, visible chert increases together with delta(13)C(PDB) values from the middle Bathonian and reaches peak values in the Callovian-Oxfordian. In basinal sections in Umbria-Marche, a sharp increase in visible chert is observed at this level within the Calcari Diasprigni. A drop of delta(13)C values towards + 2 parts per thousand occurs in the Kimmeridgian and coincides with a decrease of visible chert in outcrop. The observed delta(13)C positive anomalies during the early Bajocian and the Callovian-Oxfordian may record changes in global climate towards warmer, more humid periods characterised by increased nutrient mobilisation and increased carbon burial. High biosiliceous (radiolarians, siliceous sponges) productivity and preservation appear to coincide with the delta(13)C positive anomalies, when the production of platform carbonates was subdued and ceased in many areas, with a drastic reduction of periplatform ooze input in many Tethyan basins. The carbon and silica cycles appear to be linked through global warming and increased continental weathering. Hydrothermal events related to extensive rifting and/or accelerated oceanic spreading may be the endogenic driving force that created a perturbation of the exogenic system (excess CO2 into the atmosphere and greenhouse conditions) reflected by the positive delta(13)C shifts and biosiliceous episodes.