Intracardiac versus extracardiac shunt in a young man with ischaemic stroke

A 24-year-old man with a history of recent ischaemic stroke was diagnosed with patent foramen ovale (PFO) and referred for closure at our hospital. At admission, besides low peripheral oxygen saturation (88%), physical examination was otherwise normal. We performed intraprocedural transoesophageal echocardiogram that revealed no PFO, although agitated saline injection demonstrated bubbles lately on the left atrium. The atrial septum could not be crossed. We suspected an extracardiac shunt, so pulmonary angiograms were performed that revealed the presence of a left pulmonary arteriovenous malformation (PAVM). A Konar-MF Occluder was used to occlude the PAVM, with a satisfactory result. At 6 months follow-up, the patient had normal peripheral oxygen saturation and a new pulmonary angiogram showed no residual shunt. Intrapulmonary shunts are a rare and under-recognised cause of paradoxical emboli in young patients; physicians should be aware of this diagnosis as percutaneous occlusion is indicated and critical to avoid recurrent ischaemic episodes.

Bioinformatics and expression analysis of the Xeroderma Pigmentosum complementation group C (XPC) of Trypanosoma evansi in Trypanosoma cruzi cells

Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.

A sudden turner of events

The authors report the case of an 18-year-old woman with Turner Syndrome and aortic coarctation, who developed aortic dissection after percutaneous stenting. Surgical treatment was necessary as the lesion progressed. This case highlights both the importance of awareness as well as multidisciplinary management of this potential complication.

Echocardiographic Versus Angiographic Assessment of Patent Arterial Duct in Percutaneous Closure: Towards X-ray Free Duct Occlusion?

Device selection and procedural guidance for percutaneous ductal closure strongly rely upon angiographic and echocardiographic imaging. Current literature recognises 2D echocardiography as an essential tool for diagnosis and assessment but does not define a consistent methodology to optimise ductal measurement. There is little research comparing echocardiography with gold standard angiography for ductal measurement. Proving 2D echocardiographic ductal measurement to be equivalent to angiography could pave the way for its use as the primary modality in image guidance for percutaneous closure of the ductus. This was a retrospective study of 100 consecutive paediatric patients who underwent percutaneous ductal closure. Echocardiographic images were studied to determine ductal (a) morphology (b) dimensions (length, aortic ampulla, pulmonary end, minimum diameter) (c) size of device that would be appropriate for closure. These data were compared to corresponding measurements generated by angiographic images. Inter and intra-observer ratings were calculated to assess levels of agreement. There were significant differences between the imaging methods in classifying the morphological sub-type and ductal measurements (p < 0.005), except for length which was not found to be significantly different between modalities. Prediction of device selection from angiographic images showed excellent agreement (weighted k = 0.81). Predictions based on echocardiographic images showed a poor level of agreement (weighted k = 0.14). We found poor correlation between echocardiography and angiography for measurement, morphological assessment and device selection. Based on our findings, percutaneous arterial duct occlusion without angiographic guidance in this age group cannot be advocated.

A decade of land use contributes to changes in the chemistry, biochemistry and bacterial community structures of soils in the Cerrado

The bacterial community structures (BCSs) of Cerrado soils cultivated under conventional tillage (CT), no-tillage (NT) and under native Cerrado (NC) vegetation were evaluated using PCR/DGGE of bacterial 16S rRNA (rrs) and rpoB genes and of Pseudomonas group genes. Soil chemical analysis, microbial biomass and the enzyme activities were also evaluated and correlated with the BCS measurements. The multivariate ordinations of DGGE profiles showed differences between the BCS of the NC area and those from cultivated areas. The BCSs of the CT and NT areas also differed in all DGGE fingerprints, including changes in the profile of Pseudomonas populations, indicating that agricultural systems can also be responsible for changes within specific microbial niches, although the clearest differences were found in the rpoB profiles. The MRPP analysis demonstrated significant differences between the BCSs from different soil layers of NT areas based on all gene fingerprints and those of NC areas based on bacterial 16S rRNA and rpoB genes fingerprints. No differences were observed in the microbial fingerprints of CT samples from different depths, indicating that ploughing affected the original BCS stratification. The BCS from NC areas, based on all gene fingerprints, could be related to higher levels of soil acidity and higher amounts of MBC and of phosphatase activity. In contrast, the BCSs from cultivated areas were related to higher levels of Ca + Mg, P and K, likely as a result of a history of chemical fertilisation in these areas. The relationships between rpoB and Pseudomonas BCSs and all chemical and biochemical properties of soils were significant, according to a Mantel test (P < 0.05), indicating that the different changes in soil properties induced by soil use or management may drive the formation of the soil BCS.

Distribution of a Population of Rhizobium leguminosarum bv. trifolii among Different Size Classes of Soil Aggregates

A combination of the plant infection-soil dilution technique (most-probable-number [MPN] technique) and immunofluorescence direct count (IFDC) microscopy was used to examine the effects of three winter cover crop treatments on the distribution of a soil population of Rhizobium leguminosarum bv. trifolii across different size classes of soil aggregates (<0.25, 0.25 to 0.5, 0.5 to 1.0, 1.0 to 2.0, and 2.0 to 5.0 mm). The aggregates were prepared from a Willamette silt loam soil immediately after harvest of broccoli (September 1995) and before planting and after harvest of sweet corn (June and September 1996, respectively). The summer crops were grown in soil that had been either fallowed or planted with a cover crop of red clover (legume) or triticale (cereal) from September to April. The Rhizobium soil population was heterogeneously distributed across the different size classes of soil aggregates, and the distribution was influenced by cover crop treatment and sampling time. On both September samplings, the smallest size class of aggregates (<0.25 mm) recovered from the red clover plots carried between 30 and 70% of the total nodulating R. leguminosarum population, as estimated by the MPN procedure, while the same aggregate size class from the June sampling carried only ∼6% of the population. In June, IDFC microscopy revealed that the 1.0- to 2.0-mm size class of aggregates from the red clover treatment carried a significantly greater population density of the successful nodule-occupying serotype, AR18, than did the aggregate size classes of <0.5 mm, and 2 to 5 mm. In September, however, the population profile of AR18 had shifted such that the density was significantly greater in the 0.25- to 0.5-mm size class than in aggregates of <0.25 mm and >1.0 mm. The populations of two other Rhizobium serotypes (AR6 and AS36) followed the same trends of distribution in the June and September samplings. These data indicate the existence of structural microsites that vary in their suitabilities to support growth and protection of bacteria and that are influenced by the presence and type of plant grown in the soil.