L1 (LINE-1) retrotransposable elements provide a "fossil" record of the phylogenetic history of murid rodents

The single most difficult problem in phylogenetic analysis is deciding whether a shared taxonomic character is due to common ancestry or one that appeared independently due to convergence, parallelism, or reversion to an ancestral state. Mammalian L1 retrotransposons undergo periodic amplifications in which multiple copies of the elements are interspersed in the genome. Because these elements apparently are transmitted only by inheritance and are retained in the genome, a shared L1 amplification event can only be an inherited ancestral character. We propose that L1 amplification events can be an excellent tool for analyzing mammalian evolution and demonstrate here how we addressed several refractory problems in rodent systematics using L1 DNA as a taxonomic character.      

Changing arabinosylation patterns of wall-bound hydroxyproline in bean cell cultures

The arabinosylation patterns of wall-bound hydroxyproline in Phaseolus vulgaris L. cell suspension cultures were determined by separating free hydroxyproline and hydroxyproline-arabinose oligomers over a Bio-Gel P-2 column. Total hydroxyproline accounted for about 3.3% of wall dry weight during all growth phases of batch-cultured bean cells. The chemical arabinosylation patterns of wall-bound hydroxyproline varied during the lag phase and early log phase of the culture. First, an increase in nonglycosylated hydroxyproline occurred accompanied by a corresponding decrease in hydroxyproline tetra-arabinoside. During the early log phase the reverse happened. In later stages of growth the chemical arabinosylation patterns remained constant. The radiochemical arabinosylation patterns were also determined, after pulselabeling the cultures with [¹⁴C]proline at various times during growth, to be able to distinguish recently incorporated hydroxyproline. The time course of the arabinosylation pattern of this fraction indicated that the initial changes in the chemical pattern were due to the temporary incorporation of less extensively glycosylated hydroxyproline-containing protein into the cell wall.Abbreviations Hyp hydroxyproline - HA_n hydroxyproline arabinoside - with n arabinosyl residues - TFA trifluoroacetic acid     

Fracture prevention in COPD patients; a clinical 5-step approach

Although osteoporosis and its related fractures are common in patients with COPD, patients at high risk of fracture are poorly identified, and consequently, undertreated. Since there are no fracture prevention guidelines available that focus on COPD patients, we developed a clinical approach to improve the identification and treatment of COPD patients at high risk of fracture. We organised a round-table discussion with 8 clinical experts in the field of COPD and fracture prevention in the Netherlands in December 2013. The clinical experts presented a review of the literature on COPD, osteoporosis and fracture prevention. Based on the Dutch fracture prevention guideline, they developed a 5-step clinical approach for fracture prevention in COPD. Thereby, they took into account both classical risk factors for fracture (low body mass index, older age, personal and family history of fracture, immobility, smoking, alcohol intake, use of glucocorticoids and increased fall risk) and COPD-specific risk factors for fracture (severe airflow obstruction, pulmonary exacerbations and oxygen therapy). Severe COPD (defined as postbronchodilator FEV₁ < 50% predicted) was added as COPD-specific risk factor to the list of classical risk factors for fracture. The 5-step clinical approach starts with case finding using clinical risk factors, followed by risk evaluation (dual energy X-ray absorptiometry and imaging of the spine), differential diagnosis, treatment and follow-up. This systematic clinical approach, which is evidence-based and easy-to-use in daily practice by pulmonologists, should contribute to optimise fracture prevention in COPD patients at high risk of fracture.     

Evidence for cadherin-11 cleavage in the synovium and partial characterization of its mechanism

IntroductionEngagement of the homotypic cell-to-cell adhesion molecule cadherin-11 on rheumatoid arthritis (RA) synovial fibroblasts with a chimeric molecule containing the cadherin-11 extracellular binding domain stimulated cytokine, chemokine, and matrix metalloproteinases (MMP) release, implicating cadherin-11 signaling in RA pathogenesis. The objective of this study was to determine if cadherin-11 extracellular domain fragments are found inside the joint and if a physiologic synovial fibroblast cleavage pathway releases those fragments.MethodsCadherin-11 cleavage fragments were detected by western blot in cell media or lysates. Cleavage was interrupted using chemical inhibitors or short-interfering RNA (siRNA) gene silencing. The amount of cadherin-11 fragments in synovial fluid was measured by western blot and ELISA.ResultsSoluble cadherin-11 extracellular fragments were detected in human synovial fluid at significantly higher levels in RA samples compared to osteoarthritis (OA) samples. A cadherin-11 N-terminal extracellular binding domain fragment was shed from synovial fibroblasts after ionomycin stimulation, followed by presenilin 1 (PSN1)-dependent regulated intramembrane proteolysis of the retained membrane-bound C-terminal fragments. In addition to ionomycin-induced calcium flux, tumor necrosis factor (TNF)-α also stimulated cleavage in both two- and three-dimensional fibroblast cultures. Although cadherin-11 extracellular domains were shed by a disintegrin and metalloproteinase (ADAM) 10 in several cell types, a novel ADAM- and metalloproteinase-independent activity mediated shedding in primary human fibroblasts.ConclusionsCadherin-11 undergoes ectodomain shedding followed by regulated intramembrane proteolysis in synovial fibroblasts, triggered by a novel sheddase that generates extracelluar cadherin-11 fragments. Cadherin-11 fragments were enriched in RA synovial fluid, suggesting they may be a marker of synovial burden and may function to modify cadherin-11 interactions between synovial fibroblasts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0647-9) contains supplementary material, which is available to authorized users.     

An interesting diagnosis for a presacral mass: case report

A presacral mass can present a diagnostic dilemma for the surgical oncologist. Differential diagnoses include congenital causes such as teratoma or chordoma, neurological causes such as neurilemoma or neurofibroma or other malignancies such as lymphoma or sarcoma. Diagnosis usually requires imaging such as CT and MRI and tissue biopsy. We present an unusual cause of a presacral mass being extramedullary haematopoiesis, found incidentally in a 71 year old female. Extramedullary haematopoiesis is defined as the production of myeloid and erythroid elements outside of the bone-marrow. This diagnosis is extremely rare in the presacral area especially in a patient with no haematological abnormalities. A review of the literature is presented.     

Proteins related to lipoprotein profile were identified using a pharmaco-proteomic approach as markers for growth response to growth hormone (GH) treatment in short prepubertal children

Background  

The broad range in growth observed in response to growth hormone (GH) treatment is mainly caused by individual variations in both GH secretion and GH sensitivity. Individual GH responsiveness can be estimated using evidence-based models that predict the response to GH treatment; however, these models can be improved. High-throughput proteomics techniques can be used to identify proteins that may potentially be used as variables in such models in order to improve their predictive ability. Previously we have reported that proteomic analyses can identify biomarkers that discriminate between short prepubertal children with idiopathic short stature (ISS) who show good or poor growth in response to GH treatment. In this study we used a pharmaco-proteomic approach to identify novel factors that correlate with the growth response to GH treatment in prepubertal children who are short due to GH deficiency or ISS. The study included 128 short prepubertal children receiving GH treatment, of whom 39 were GH-deficient and 89 had ISS. Serum protein expression profiles at study start and after 1 year of GH treatment were analyzed using SELDI-TOF. Cross-validated regression and random permutation analyses were performed to identify significant correlations between protein expression patterns and the 2-year growth response to GH treatment.     

Frequent utilization of the emergency department for acute exacerbation of chronic obstructive pulmonary disease

Background

Little is known about patients who frequently visit the emergency department (ED) for acute exacerbation of chronic obstructive pulmonary disease (AECOPD). We aimed to quantify the proportion and characteristics of patients with frequent ED visits for AECOPD and associated healthcare utilization.

Methods

We conducted a retrospective cohort study of adults aged ≥40 years with at least one ED visit for AECOPD between 2010 and 2011, derived from population-based all-payer data of State ED and Inpatient Databases for two large and diverse states: California and Florida. Outcome measures were frequency of ED visits for AECOPD, 30-day ED revisits, subsequent hospitalizations, near-fatal events (AECOPD involving mechanical ventilation), and charges for both ED and inpatient services (available only for Florida) during the year after the first ED visit.

Results

The analytic cohort comprised 98,280 unique patients with 154,736 ED visits for AECOPD. During the 1-year period, 29.4% (95% CI, 29.1%-29.7%) of the patients had two or more (frequent) visits, accounting for 55.2% (95% CI, 54.9%-55.4%) of all ED visits for AECOPD. In the multivariable model, significant predictors of frequent ED visits were age 55–74 years (vs. 40–54 years), male sex, non-Hispanic white or black race, Medicaid insurance (vs. private), and lower median household income (all P < 0.001). At the visit-level, 12.3% of ED visits for AECOPD were 30-day revisit events (95% CI, 12.1%-12.4%). Additionally, 62.8% of ED visits for AECOPD (95% CI, 62.6%-63.0%) resulted in a hospitalization; patients with frequent ED visits comprised 55.5% (95% CI, 55.2%-55.8%) of all hospitalizations. Furthermore, 7.3% (95% CI, 7.3%-7.5%) of ED visits for AECOPD led to a near-fatal event; patients with frequent ED visits accounted for 64.4% (95% CI, 63.5%-65.3%) of all near-fatal events. Total charges for AECOPD were $1.94 billion (95% CI, $1.90-1.97 billion) in Florida; patients with frequent ED visits accounted for $1.07 billion (95% CI, $1.04-1.09 billion).

Conclusions

In this large cohort study, we found that 29% had frequent ED visits for AECOPD and that lower socioeconomic status was significantly associated with a higher frequency of ED visits. Individuals with frequent ED visits for AECOPD accounted for a substantial amount of healthcare utilization and financial burden.     

Purification and characterization of the inducible a agglutinin of Saccharomyces cerevisiae.

A cell surface glycoprotein induced by the mating pheromone alpha factor in Saccharomyces cerevisiae a cells has been purified to homogeneity. At 4 x 10(-9) M it strongly inhibits mating-type-specific agglutination between a and alpha cells. The protein is solely O-glycosylated. It consists of 29% carbohydrate and its apparent molecular mass is 22 kd on SDS gels. After HF treatment it behaves like a protein of 13 kd; therefore its true molecular mass probably is close to 18 kd. Mild periodate treatment destroys the biological activity of the purified protein. The protein contains one cysteine, no arginine, and 27% of the amino acids are serine and threonine residues, two thirds of which are glycosylated. With a polyclonal antibody the glycoprotein can already be detected at the cell surface 15 min after pheromone addition. The inducible antigen is not expressed in a specific phase of the cell cycle; it first appears exclusively on the growing bud. Mother cells express the antigen on their surface only after the daughter cells have separated; it is then localized at the tip of the pear-shaped 'shmoo'. Using the secretory ts-mutant sec 18 is shown that a mannosylated precursor of a agglutinin accumulates at the endoplasmic reticulum.     

Potent V2 vasopressin antagonists with structural changes at their C-terminals

A variety of structural changes were made in the C-terminals of four potent antidiuretic (V2) antagonists. The parent analogs were all derivatives of [1-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid)]arginine-vasopressin, d(CH2)5AVP, namely d(CH2)5[D-Phe2,Ile4]AVP, d(CH2)5[D-Ile2,Ile4]AVP, d(CH2)5[D-Tyr(Et)2, Val4]AVP and d(CH2)5[D-Tyr(Et)2,Ile4]AVP. A number of amino acid amides were substituted for the C-terminal 9-glycinamide without reducing their V2-antagonistic potencies in rats. Many non-amino acid structures were also tolerated at the C-terminals of these antagonists and this end of these peptides can be prolonged without interfering with antagonistic potencies. Such altered V2-antagonists may be useful for the development of radioactive ligands, affinity labels and in affinity columns for studies on antidiuretic receptors. These C-terminal modifications also provide useful information for the further development of potent and specific V2-antagonists which can be valuable pharmacological tools and also promise to become useful clinically for the treatment of excessive water retention.