Unprecedented W2(0) quadruply bonded complex supported by π-donor ligands.

A quadruply bonded complex W2(DippF)2K2 with a W2(0) core was synthesized and structurally characterized. The observed W-W distance of 2.407(1) Å and DFT calculations are consistent to the unprecedented electronic structure in D(2h) symmetry of σ(2)π(2)π(2)δ(2)δ(2)δ*(2) where the HOMO is the δ* orbital.

Phylogeographic structure and karyotypic diversity of the Brazilian shrew mouse ( Blarinomys breviceps, Sigmodontinae) in the Atlantic Forest.

Blarinomys breviceps possesses cryptic and burrowing habits with poorly documented genetics and life history traits. Due to its rarity, only a few specimens and DNA sequences have been deposited in collections worldwide. Here, we present the most comprehensive cytogenetic and molecular characterization of this rare genus. Phylogenetic analyses based on partial cytochrome b sequences were performed, attempting to establish the relationships among individuals with distinct karyotypes along the geographic distribution of the genus in the Atlantic Forest. Classical and molecular cytogenetics, using banding patterns and FISH of telomeric and whole chromosome X-specific painting probes (obtained from the Akodontini Akodon cursor) were used to characterize and compare the chromosomal complements. Molecular phylogenetic analyses recovered 2 main geographically structured clades, northeastern and southeastern with pairwise sequence divergences among specimens varying between 4.9 and 8.4%. Eight distinct karyomorphs are described: (A) 2n = 52 (50A, XX), (B) 2n = 52 (48A, XY+2Bs), (C) 2n = 45 (42A, XY+1B), (D) 2n = 43 (37A, XX+4Bs), (E) 2n = 37 (34A, XY+1B), (F) 2n = 34 (32A, XX), (G) 2n = 31 (27A, XX+2Bs), (H) 2n = 28 (26A, XY), all with the same number of autosomal arms (FN(A) = 50). Variation of 0-4 supernumerary chromosomes (Bs) presenting heterogeneity in morphology and distribution of interstitial telomeric sequences (ITSs) is reported. ITSs are also found in some metacentric autosomes. The phylogeographic separation between 2 major lineages with high levels of genetic divergence, and the wide karyotypic diversity indicate that B. breviceps is a diverse group that warrants taxonomic re-evaluation.

A new allopatric lineage of the rodent Deltamys (Rodentia: Sigmodontinae) and the chromosomal evolution in Deltamys kempi and Deltamys sp.

Deltamys Thomas 1917 is a poorly studied and rarely collected taxon of Akodontini (Sigmodontinae). The single described species, Deltamys kempi (DKE), has a basic karyotype with a diploid number of 2n = 37 in males and 2n = 38 in females, a fundamental number FN = 38 for both sexes, and an X(1)X(1)X(2)X(2)/X(1)X(2)Y sex determination system. Herein, a new allopatric form, Deltamys sp. (DSP), is reported, based on specimens from southern Brazil, with 2n = 40, FN = 40 and XX/XY sex chromosomes. We describe the karyotype and mechanism of chromosomal differentiation between both Deltamys complements. Phylogenetic analyses, based on the complete sequence (1,140 bp) of the mitochondrial cytochrome b gene, grouped Deltamys sp. as sister species to D. kempi, with up to 12% genetic divergence between them. The GTG-banding patterns show complete autosomal correspondence between D. kempi and Deltamys sp. and identify a tandem rearrangement involving DSP7, DSP19 and DKE4 that is responsible for the differences in 2n and FN. Chromosome painting with Akodon paranaensis chromosome 21 (a small metacentric akodont marker) paint revealed total homology with the smallest acrocentric Deltamys sp. chromosome, DSP19. This suggests the occurrence of a pericentric inversion or centromeric shift when compared to other akodontines, with a posterior tandem rearrangement giving rise to DKE4. In DKE, large blocks of pericentromeric constitutive heterochromatin are present on the autosomes and the X, and the Y/autosome has an entirely heterochromatic short arm. In DSP, small heterochromatic blocks are observed on autosomes and X, and the Y is a very small, mostly heterochromatic acrocentric. The cytogenetic analyses suggest that the Deltamys sp. karyotype is ancestral, with the derived condition resulting from a tandem fusion (DSP7 + DSP19) and the Y/autosome translocation giving rise to the multiple sex chromosome system. The autosomal rearrangements, the differences in CBG-banding patterns and Ag-NOR localization, as well as the presence of X(1)X(1)X(2)X(2)/X(1)X(2)Y and XX/XY sex determination mechanisms, possibly acting as a reproductive barrier, and the phylogenetic position within the Deltamys genus, with high genetic divergence, call for a taxonomic review of the genus.

Non-telomeric sites as evidence of chromosomal rearrangement and repetitive (TTAGGG)n arrays in heterochromatic and euchromatic regions in four species of Akodon (Rodentia, Muridae).

Comparative studies among four species--Akodonazarae (2n = 38), A. lindberghi (2n = 42), A. paranaensis (2n = 44) and A. serrensis (2n = 46)--employing classic cytogenetics (C- and G-bands) and fluorescence in situ hybridization with telomeric (TTAGGG)n sequencesare reported here. Non-telomeric signals in addition to the regular telomeric sites were detected in three species:A. azarae, A. lindberghi and A. serrensis. One interstitial telomeric site (ITS) was observed proximally at the long arm of chromosome 1 of A. azarae. The comparison of G-banding patterns among the species indicated that the ITS was due to a tandem fusion/fission rearrangement. Non-telomeric signals of A. lindberghi and A. serrensis were not related to chromosomal rearrangements; instead, the sequences co-localized with (i) heterochromatic regions of all chromosomes in A. serrensis; (ii) some heterochromatic regions in A. lindberghi, and (iii) both euchromatic and heterochromatic regions in the metacentric pair of A. lindberghi. These exceptional findings revealed that ITS in Akodon can be related to chromosomal rearrangements and repetitive sequences in the constitutive heterochromatin and that the richness of TTAGGG-like sequences in the euchromatin could be hypothesized to be a result of amplification of the referred sequence along the chromosome arms.

Isolated liver transplantation for decompensated end-stage liver disease in children with intestinal failure.

Cholestasis progressing to end-stage liver disease (ESLD) is common in intestinal failure (IF) in infants. Isolated liver transplantation (OLT) is performed when eventual enteral sufficiency is expected. We reviewed our experience with OLT for ESLD in patients with residual IF. From 1998 to 2004, four IF patients underwent OLT for ESLD at our institution. Three were performed as UNOS status I for acute decompensation of chronic liver failure; one other with severe cholestasis with a living donor. The living donor recipient died within months after OLT of chronic respiratory failure despite normal liver function. One recipient remains on parenteral nutrition (PN) and continues to receive partial enteral feeds with normal liver function. Two other recipients became enterally sufficient after the OLT. Biliary complications occurred in two patients, one with late hepatic artery thrombosis. Resolution was achieved with serial balloon dilatations and the other by conversion from duct-to-duct anastomosis to a choledochoduodenostomy. The morbidity of OLT for this indication is higher than for others likely because of comorbidities like sepsis and pulmonary insufficiency. OLT is complicated further by the attempt to maximally preserve residual bowel length for the biliary reconstruction. OLT can be an emergent life-saving procedure in IF patients despite higher morbidity. Improved liver function and diminished portal pressures may shorten the time to enteral sufficiency. Management of parenteral nutrition after OLT can avoid ESLD and eliminate small bowel transplantation in selected patients.

Comparison of three different solid-phase microextraction fibres for analysis of essential oils in yacon (Smallanthus sonchifolius) leaves.

A headspace solid-phase microextraction (HS-SPME) procedure based on three commercialised fibers (100 microm polydimethylsiloxane, 65 microm polydimethylsiloxane-divinylbenzene and 50/30 microm divinylbenzene-Carboxen-polydimethylsiloxane) is presented for the determination of a selected essential oils in dried leaves of yacon (Smallanthus sonchifolius). The extraction performances of these compounds were compared using fibers with one, two and three coatings. The optimal experimental procedures for the adsorption and desorption of target compounds were determined. Significant parameters affecting sorption process such as sample weight, sorption and desorption time and temperature were optimised and discussed. Finally, the optimised procedures were applied successfully for the determination of these compounds in various yacon species. The relative concentration factors of three characteristic components of yacon were measured for relative evaluation of the fiber efficiency. Main essential oils were isolated from dried yacon leaves by appropriate solid-phase microextraction fiber and semi-quantitative analysis of the target volatiles was conducted by gas chromatography-flame ionisation detection (GC-FID) using a capillary column. Three compounds--beta-pinene, caryophylene and y-cadinene were found as the predominant essential oils. Its relative content was important for specification of yacon varieties. Solid-phase microextraction in combination with gas chromatography enabled a rapid and simple determination of relative content of essential oils in yacon.

Hematologic differences in heterophile-positive and heterophile-negative infectious mononucleosis.

Infectious mononucleosis (IM) due to all causes is characterized by atypical lymphocytosis. We sought to compare hematologic parameters of infectious mononucleosis due to Epstein-Barr virus (EBV) infection (heterophile antibody (HA) positive) with mononucleosis due to other causes. Mono-Latex Slide Agglutination Test results and complete blood counts (CBC) of 147 patients with mononucleosis were retrospectively analyzed. Leukocyte count, absolute lymphocyte count, and presence of atypical lymphocytes in EBV-positive and EBV-negative groups were statistically compared. We analyzed 68 EBV-positive and 79 EBV-negative cases. EBV-positive patients were significantly younger than EBV-negative patients were. Mean total WBC count and mean absolute lymphocyte count were significantly higher in EBV-positive patients. Absolute lymphocytosis, absolute leukocytosis, and atypical lymphocytosis were also significantly more frequent in EBV-positive patients. Leukopenia was more frequently seen in EBV-negative patients.

Determination of acrylonitrile in materials in contact with foodstuffs.

Monitoring of the content of free acrylonitrile in plastics used for the preparation of viands is necessary due to its negative effect on human health. A content of 20 ppb is the maximal value of free acrylonitrile in such samples. In this case, head-space gas chromatography is most favourable analytical method when combined with the standard addition method together with a mass-spectrometry detector because of a very low concentration of the analyte. In samples taken for analysis, the content of free acrylonitrile was found to be within 5.1 and 10.3 ppb (microg/kg).

Hemoptysis secondary to pulmonary pseudoaneurysm 30 years after a gunshot wound.

A 49-year-old man presented with intermittent hemoptysis from a traumatic pulmonary artery pseudoaneurysm 30 years following a thoracic gunshot wound. The patient was asymptomatic for 28.5 years, when he began experiencing recurrent hemoptysis, chest pain, and a cough. A left lower lobe mass on chest x-ray film was investigated with contrast-enhanced computed tomography and pulmonary angiogram confirming a 1.5-cm pseudoaneurysm. Intraluminal coil embolization was attempted, but a left lower lobectomy was ultimately necessary to treat persistent hemoptysis.

Fatal neonatal echovirus 6 infection: autopsy case report and review of the literature.

A full-term, healthy male neonate was delivered by caesarian section to a 26-year-old primigravida woman who had a history of fever and upper respiratory tract infection. On the fourth day of life, the neonate developed a sepsis-like syndrome, acute respiratory and renal failure, and disseminated intravascular coagulopathy. He died 13 days after birth. Postmortem examination revealed jaundice, anasarca, massive hepatic necrosis, adrenal hemorrhagic necrosis, renal medullary hemorrhage, hemorrhagic noninflammatory pneumonia, and severe encephalomalacia. Echovirus type 6 was isolated from blood, liver, and lungs. Although uncommon, echovirus type 6 infection may produce a spectrum of pathologic findings similar to those seen with the more commonly virulent echovirus type 11.