Structure and mechanism of Zn2+-transporting P-type ATPases.

Zinc is an essential micronutrient for all living organisms. It is required for signalling and proper functioning of a range of proteins involved in, for example, DNA binding and enzymatic catalysis. In prokaryotes and photosynthetic eukaryotes, Zn(2+)-transporting P-type ATPases of class IB (ZntA) are crucial for cellular redistribution and detoxification of Zn(2+) and related elements. Here we present crystal structures representing the phosphoenzyme ground state (E2P) and a dephosphorylation intermediate (E2·Pi) of ZntA from Shigella sonnei, determined at 3.2 Å and 2.7 Å resolution, respectively. The structures reveal a similar fold to Cu(+)-ATPases, with an amphipathic helix at the membrane interface. A conserved electronegative funnel connects this region to the intramembranous high-affinity ion-binding site and may promote specific uptake of cellular Zn(2+) ions by the transporter. The E2P structure displays a wide extracellular release pathway reaching the invariant residues at the high-affinity site, including C392, C394 and D714. The pathway closes in the E2·Pi state, in which D714 interacts with the conserved residue K693, which possibly stimulates Zn(2+) release as a built-in counter ion, as has been proposed for H(+)-ATPases. Indeed, transport studies in liposomes provide experimental support for ZntA activity without counter transport. These findings suggest a mechanistic link between PIB-type Zn(2+)-ATPases and PIII-type H(+)-ATPases and at the same time show structural features of the extracellular release pathway that resemble PII-type ATPases such as the sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA) and Na(+), K(+)-ATPase. These findings considerably increase our understanding of zinc transport in cells and represent new possibilities for biotechnology and biomedicine.

Prospective cohort study on surgical wounds comparing a polyhexanide-containing biocellulose dressing with a dialkyl-carbamoyl-chloride-containing hydrophobic dressing.

OBJECTIVE: Postsurgery dressing changes in diabetic foot amputation wounds and surgical wounds healing by secondary intention are often conducted in the operating room under general anesthesia. A prospective comparative cohort study was performed in 60 patients (n = 60: n = 30/n = 30) with secondary-intention surgical wounds (82% had forefoot and/or digit[s] amputations) to compare 2 different dressing types. METHOD: Patients at the study center gave informed written consent, after which they were randomly allocated to one of the treatment groups. Group A received a biocellulose dressing with polyhexanide, and group B a hydrophobic dressing with dialkyl-carbamoyl-chloride. In both groups, gauze was used as secondary dressing and fixed with a film dressing. One day after surgery, the dressings were removed by the surgeon and patient-reported pain and dressing adherence/integrity were evaluated. The number of patients that required general anesthesia was determined during the procedure and afterward. RESULTS: All patients (n = 60; n = 30/n = 30) were included in the intention-to-treat analysis. Pain levels in group A were significantly (t (59) = 4.026, P < .000) lower upon dressing removal, when compared with group B; in group A, n = 21 reported no pain versus n = 8 (26%) for group B. In group A, the dressing adhered in 7 subjects (23%) versus n = 27 (90%) of cases in group B (P = .000). No anesthesia was required for the patients in group A, contrary to group B, where 16% of patients received general anesthesia for dressing removal. CONCLUSION: Pain levels were significantly lower and the dressing adhered significantly less in group A, compared with group B, demonstrating a better quality of life for the patients in group A.

Legume anchor markers link syntenic regions between Phaseolus vulgaris, Lotus japonicus, Medicago truncatula and Arachis.

We have previously described a bioinformatics pipeline identifying comparative anchor-tagged sequence (CATS) loci, combined with design of intron-spanning primers. The derived anchor markers defining the linkage position of homologous genes are essential for evaluating genome conservation among related species and facilitate transfer of genetic and genome information between species. Here we validate this global approach in the common bean and in the AA genome complement of the allotetraploid peanut. We present the successful conversion of approximately 50% of the bioinformatics-defined primers into legume anchor markers in bean and diploid Arachis species. One hundred and four new loci representing single-copy genes were added to the existing bean map. These new legume anchor-marker loci enabled the alignment of genetic linkage maps through corresponding genes and provided an estimate of the extent of synteny and collinearity. Extensive macrosynteny between Lotus and bean was uncovered on 8 of the 11 bean chromosomes and large blocks of macrosynteny were also found between bean and Medicago. This suggests that anchor markers can facilitate a better understanding of the genes and genetics of important traits in crops with largely uncharacterized genomes using genetic and genome information from related model plants.

A general pipeline for the development of anchor markers for comparative genomics in plants.

BACKGROUND: Complete or near-complete genomic sequence information is presently only available for a few plant species representing a large phylogenetic diversity among plants. In order to effectively transfer this information to species lacking sequence information, comparative genomic tools need to be developed. Molecular markers permitting cross-species mapping along co-linear genomic regions are central to comparative genomics. These "anchor" markers, defining unique loci in genetic linkage maps of multiple species, are gene-based and possess a number of features that make them relatively sparse. To identify potential anchor marker sequences more efficiently, we have established an automated bioinformatic pipeline that combines multi-species Expressed Sequence Tags (EST) and genome sequence data. RESULTS: Taking advantage of sequence data from related species, the pipeline identifies evolutionarily conserved sequences that are likely to define unique orthologous loci in most species of the same phylogenetic clade. The key features are the identification of evolutionarily conserved sequences followed by automated design of intron-flanking Polymerase Chain Reaction (PCR) primer pairs. Polymorphisms can subsequently be identified by size- or sequence variation of PCR products, amplified from mapping parents or populations. We illustrate our procedure in legumes and grasses and exemplify its application in legumes, where model plant studies and the genome- and EST-sequence data available have a potential impact on the breeding of crop species and on our understanding of the evolution of this large and diverse family. CONCLUSION: We provide a database of 459 candidate anchor loci which have the potential to serve as map anchors in more than 18,000 legume species, a number of which are of agricultural importance. For grasses, the database contains 1335 candidate anchor loci. Based on this database, we have evaluated 76 candidate anchor loci with respect to marker development in legume species with no sequence information available, demonstrating the validity of this approach.

[Injection of synthol in a bodybuilder can cause chronic wounds and ulceration]. / Injektion af synthololie hos bodybuilder gav kroniske sår og deformerende ar.

In this case report we present a 45-year-old male bodybuilder, who had injected synthol and paraffin oil in both upper arms for augmentation purposes. This led to a circumference of 66 cm of his upper arms. His arms were rock solid and clearly deformed. Few years after the injections the patient suffered from spontaneous ulcerations on both arms. Conservative wound treatment with antibiotics and compression therapy had good effect on the ulcers of the right arm. The left arm needed surgical revision and negative pressure wound therapy preparing the tissue for a split skin graft.

[Marjolin's ulcer in a 54-year-old skin graft].

Marjolin's ulcer (MU) is a malignant degeneration of a chronic wound and spinocellular carcinoma is the most common type. MU is described as being aggressive in nature and carries a high incidence of metastases. A 71-year-old man developed spinocellular carcinoma 54 years after a primary amputation and a construction of a skin graft due to a severe foot trauma. The carcinoma was excised and a forefoot amputation was performed.

Copper-transporting P-type ATPases use a unique ion-release pathway.

Heavy metals in cells are typically regulated by PIB-type ATPases. The first structure of the class, a Cu(+)-ATPase from Legionella pneumophila (LpCopA), outlined a copper transport pathway across the membrane, which was inferred to be occluded. Here we show by molecular dynamics simulations that extracellular water solvated the transmembrane (TM) domain, results indicative of a Cu(+)-release pathway. Furthermore, a new LpCopA crystal structure determined at 2.8-Å resolution, trapped in the preceding E2P state, delineated the same passage, and site-directed-mutagenesis activity assays support a functional role for the conduit. The structural similarities between the TM domains of the two conformations suggest that Cu(+)-ATPases couple dephosphorylation and ion extrusion differently than do the well-characterized PII-type ATPases. The ion pathway explains why certain Menkes' and Wilson's disease mutations impair protein function and points to a site for inhibitors targeting pathogens.

[Calciphylaxis]. / Kalcifylaksi.

Calciphylaxis is a serious condition including ischaemic, nodular necrosis of the subcutaneous tissue and occlusion of small and medium-sized arteries. The prevalence of calciphylaxis among patients on chronic haemodialysis constitutes 1-4 percent. The condition is associated with high mortality due to co-morbidity. Calciphylaxis seems to be preventable by optimized control of calcium-phosphorous metabolism in susceptible individuals. New and promising therapies are evolving. It is important to focus on this condition in order to provide the relevant therapy to the affected cases.