Identification and subtyping of Francisella by pyrosequencing and signature matching of 16S rDNA fragments

AIMS

To analyse the V1 region of the 16S rDNA gene by a universal pyrosequencing protocol to identify and subtype Francisella in 31 strains from a repository collection and 96 patient isolates.

METHODS AND RESULTS

Pyrosequencing was used to determine the nucleotide sequence of PCR amplification products of the variable region (V1) of the 16S rDNA from 31 repository strains and 96 isolates from Swedish patients with ulceroglandular tularaemia. Pyrosequencing resulted in a 37 nucleotide sequence, specific for Francisella sp., for all repository strains and patient samples analysed. In addition, the isolates could be divided into two groups based on the analysis of a single nucleotide polymorphism in the sequence: one group included Francisella tularensis ssp. tularensis, ssp. holarctica and ssp. mediasiatica, whereas the other group included Francisella tularensis ssp. novicida and other species of Francisella. The analysis of samples taken from patients suffering from ulceroglandular tularaemia revealed that all isolates belonged to the first group comprising subspecies of F. tularensis virulent for humans.

CONCLUSIONS

The pyrosequencing analysis of the 16S rDNA V1 is a useful molecular tool for the rapid identification of suspected isolates of Francisella sp. in clinical or environmental samples.

SIGNIFICANCE AND IMPACT OF THE STUDY

Virulent F. tularensis ssp. causing ulceroglandular tularaemia, or those with a potential to be used in a bioterrorism event, could rapidly be discriminated from subspecies less virulent for humans.

Orbital Kondo effect in cobalt-benzene sandwich molecules

We study a Co-benzene sandwich molecule bridging the tips of a Cu nanocontact as a realistic model of correlated molecular transport. To this end we employ a recently developed method for calculating the correlated electronic structure and transport properties of nanoscopic conductors. When the molecule is slightly compressed by the tips of the nanocontact the dynamic correlations originating from the strongly interacting Co 3d shell give rise to an orbital Kondo effect while the usual spin Kondo effect is suppressed due to Hund's rule coupling. This nontrivial Kondo effect produces a sharp and temperature-dependent Abrikosov-Suhl resonance in the spectral function at the Fermi level and a corresponding Fano line shape in the low bias conductance.

[Periarticular diseases of the hip in young adults]

Multiple periarticular structures are present around the hip joint: tendons, bursae, muscles and entheses, fascias, nerves and vessels. Periarticular diseases of the hip in young adults include, in decreasing order of functional impairment: posttraumatic lesions of muscles and tendons that should not be overlooked because of the risk of functional sequelae, enthesopathy detected on plain films and ultrasound, snapping hip syndrome frequent in athletes and tunnel syndromes (such as compression of the lateral femoral cutaneous nerve where ultrasound is valuable). The main pitfalls to avoid are the stress fracture, trauma to a pelvic muscle and calcium deposition.

Critical comparison of electrode models in density functional theory based quantum transport calculations

We study the performance of two different electrode models in quantum transport calculations based on density functional theory: parametrized Bethe lattices and quasi-one-dimensional wires or nanowires. A detailed account of implementation details in both the cases is given. From the systematic study of nanocontacts made of representative metallic elements, we can conclude that the parametrized electrode models represent an excellent compromise between computational cost and electronic structure definition as long as the aim is to compare with experiments where the precise atomic structure of the electrodes is not relevant or defined with precision. The results obtained using parametrized Bethe lattices are essentially similar to the ones obtained with quasi-one-dimensional electrodes for large enough cross-sections of these, adding a natural smearing to the transmission curves that mimics the true nature of polycrystalline electrodes. The latter are more demanding from the computational point of view, but present the advantage of expanding the range of applicability of transport calculations to situations where the electrodes have a well-defined atomic structure, as is the case for carbon nanotubes, graphene nanoribbons, or semiconducting nanowires. All the analysis is done with the help of codes developed by the authors which can be found in the quantum transport toolbox ALACANT and are publicly available.

Phenotypic and genotypic characterization of carcinomas of the papilla of Vater has prognostic and putative therapeutic implications

We further characterize the heterogeneous carcinomas of the papilla of Vater (CPVs) in relation to various clinicopathologic patient characteristics and patient survival. Of the 71 reevaluated CPVs, 32 were intestinal, 26 were pancreatobiliary, 6 were mixed, 4 were mucinous, and 3 were poorly differentiated carcinomas. The prevalence of cytokeratin 20 and cytokeratin 7 correlated with the intestinal (25/32 [78%] vs 13/32 [41%]) and pancreatobiliary (6/26 [23%] vs 24/26 [92%]) phenotypes. CDX2 was found in mucinous (3/4 [75%]), intestinal (7/32 [22%]), and some mixed (1/6 [1%]) CPVs. A KRAS mutation was detected in all poorly differentiated CPVs and in about 20% of each of the other types. In multivariate analyses, tumor type, local tumor spread, and lymph node metastases were independent prognostic factors of patient survival. We provide further evidence of the prognostic relevance of the phenotypic and genotypic diversity of CPVs. Besides the poorly differentiated CPV, the most common KRAS wild type makes them a putative target for an anti-epidermal growth factor receptor therapy.

Interventional musculoskeletal ultrasonography: Precautions and contraindications

In recent years ultrasonography (US) has emerged as the imaging technique of choice for guiding diagnostic and therapeutic procedures including those related to the musculoskeletal system. However, the absence of ionizing radiation and the elevated safety of the method must not lead us to forget that there are precautions and contraindications to keep in mind, which are crucial to the protection of both the patient and the physician.Among these precautions it is first of all essential to obtain the patient's accurate clinical history including current medication, particularly if it involves drugs influencing the blood clotting, and information related to possible allergies. The patient should furthermore receive detailed information concerning the procedure (sterile precautions as well as possible side-effects of the drugs which will be injected). In addition to this, there must be a close contact between the radiologist and the patient's general physician (GP) in order to obtain the best possible result of the procedure.

Kondo effect and conductance of nanocontacts with magnetic impurities

We study the impact of dynamical correlations on the electronic structure and coherent transport properties of Cu nanocontacts hosting a single magnetic impurity (Ni, Co, Fe) in the contact region. The strong dynamical correlations of the impurity 3d electrons are fully taken into account by combining density-functional calculations with a dynamical treatment of the impurity 3d shell in the one-crossing approximation. We find that dynamical correlations give rise to the Kondo effect and lead to Fano features in the coherent transport characteristics similar to those observed in related experiments.

Surgical strategies for treatment of malignant pancreatic tumors: extended, standard or local surgery?

Tumor related pancreatic surgery has progressed significantly during recent years. Pancreatoduodenectomy (PD) with lymphadenectomy, including vascular resection, still presents the optimal surgical procedure for carcinomas in the head of pancreas. For patients with small or low-grade malignant neoplasms, as well as small pancreatic metastases located in the mid-portion of pancreas, central pancreatectomy (CP) is emerging as a safe and effective option with a low risk of developing de-novo exocrine and/or endocrine insufficiency. Total pancreatectomy (TP) is not as risky as it was years ago and can nowadays safely be performed, but its indication is limited to locally extended tumors that cannot be removed by PD or distal pancreatectomy (DP) with tumor free surgical margins. Consequently, TP has not been adopted as a routine procedure by most surgeons. On the other hand, an aggressive attitude is required in case of advanced distal pancreatic tumors, provided that safe and experienced surgery is available. Due to the development of modern instruments, laparoscopic operations became more and more successful, even in malignant pancreatic diseases. This review summarizes the recent literature on the above mentioned topics.

[Metastatic lesions to the pancreas. When is resection reasonable?]

BACKGROUND

The significance of pancreatic resection for pancreatic metastatic lesions has not yet been sufficiently investigated. A retrospective analysis of patients undergoing pancreatic resections for pancreatic metastases was conducted.

MATERIAL AND METHODS

Twenty patients were resected due to metastatic lesions to the pancreas. Histopathological findings were: renal cell carcinoma (n=9), colon carcinoma (n=1), malignant schwannoma (n=2), leiomyosarcoma (n=2), teratocarcinoma (n=1), adenocarcinoma of the oesophagus (n=1), gallbladder carcinoma (n=1), malignant melanoma (n=1), gastrointestinal stromal tumor (n=1), and spindle cell tumor (n=1). Operative procedures were standard pancreaticoduodenectomy (n=6), pylorus-preserving pancreaticoduodenectomy (n=6), and distal pancreatectomy (n=8).

RESULT

The overall 5-year survival rate was 61%, for patients with renal cell carcinoma 100%.

CONCLUSION

Pancreatic metastasectomy is a reasonable therapeutic option in suited patients. Patients with pancreatic metastases of renal cell carcinoma achieved excellent prognoses after radical resection.

Conditions for development of powdery mildew of tomato caused by Oidium neolycopersici

Oidium neolycopersici causes severe powdery mildew on all aerial parts of tomato, excluding the fruit. The objective of the present work was to examine factors that influence the development of O. neolycopersici on tomato and to identify potential methods for managing tomato powdery mildew. Under controlled conditions, the highest rates of conidial germination were observed at 25 degrees C, 99% relative humidity (RH) and minimal light, and the lowest on leaves adjacent to fruits. Optimal conditions for appressoria formation were 25 degrees C, RH ranging from 33 to 99%, and 1,750 lux light intensity. More conidia were formed at 20 degrees C, 70 to 85% RH, and 5,150 lux light intensity than at 16 and 26 degrees C, 99% RH, and 480 to 1,750 lux, respectively. Conidia survived and remained capable of germination for over four months when initially incubated at lower temperatures and higher RH, as compared with their fast decline under more extreme summer shade conditions. In growth chamber experiments, disease did not develop at 28 degrees C. Within the range of 70 to 99% RH, disease was less severe under the higher RH than the drier conditions. Disease was also less severe at lower light intensities. Data collected in three commercial-like greenhouse experiments involving various climate regimes were used to draw correlations regarding the effects of temperature and RH on the development of epidemics. Severity of powdery mildew was positively correlated with the duration of the range 15 to 25 degrees C, 1 to 4 weeks before disease evaluation (BDE), RH levels of 60 to 90% at 2 to 4 weeks BDE, and RH of 50 to 60% during the week BDE. Conversely, disease was negatively correlated with the duration of temperatures in the low and high ranges (5 to 15 degrees C and 35 to 40 degrees C) at 1 to 4 weeks BDE, with the duration of RH levels of 40% and below at 1 to 4 weeks BDE, and with 50 to 60% RH during the third week BDE. High (90 to 100%) RH was also negatively correlated with disease severity. These results suggest that the combination of high temperatures and low RH may help reduce O. neolycopersici powdery mildew severity in greenhouse tomatoes.