Synchronous down-modulation of miR-17 family members is an early causative event in the retinal angiogenic switch

Six members of the microRNA-17 (miR-17) family were mapped to three different chromosomes, although they share the same seed sequence and are predicted to target common genes, among which are those encoding hypoxia-inducible factor-1α (HIF1A) and VEGFA. Here, we evaluated the in vivo expression profile of the miR-17 family in the murine retinopathy of prematurity (ROP) model, whereby Vegfa expression is highly enhanced at the early stage of retinal neovascularization, and we found simultaneous reduction of all miR-17 family members at this stage. Using gene reporter assays, we observed binding of these miRs to specific sites in the 3′ UTRs of Hif1a and Vegfa. Furthermore, overexpression of these miRs decreased HIF1A and VEGFA expression in vitro. Our data indicate that this miR-17 family elicits a regulatory synergistic down-regulation of Hif1a and Vegfa expression in this biological model. We propose the existence of a coordinated regulatory network, in which diverse miRs are synchronously regulated to target the Hif1a transcription factor, which in turn, potentiates and reinforces the regulatory effects of the miRs on Vegfa to trigger and sustain a significant physiological response

Are ICD-10 codes appropriate for performance assessment in asthma and COPD in general practice? Results of a cross sectional observational study

BACKGROUND: The increasing prevalence and impact of obstructive lung diseases and new insights, reflected in clinical guidelines, have led to concerns about the diagnosis and therapy of asthma and COPD in primary care. In Germany diagnoses written in medical records are used for reimbursement, which may influence physicians' documentation behaviour. For that reason it is unclear to what respect ICD-10 codes reflect the real problems of the patients in general practice. The aim of this study was to assess the appropriateness of the recorded diagnoses and to determine what diagnostic information is used to guide medical treatment. METHODS: All patients with lower airway symptoms (n = 857) who had attended six general practices between January and June 2003 were included into this cross sectional observational study. Patients were selected from the computerised medical record systems, focusing on ICD-10-codes concerning lower airway diseases (J20-J22, J40-J47, J98 and R05). The performed diagnostic procedures and actual medication for each identified patient were extracted manually. Then we examined the associations between recorded diagnoses, diagnostic procedures and prescribed treatment for asthma and COPD in general practice. RESULTS: Spirometry was used in 30% of the patients with a recorded diagnosis of asthma and in 58% of the patients with a recorded diagnosis of COPD. Logistic regression analysis showed an improved use of spirometry when inhaled corticosteroids were prescribed for asthma (OR = 5.2; CI 2.9–9.2) or COPD (OR = 4.7; CI 2.0–10.6). Spirometry was also used more often when sympathomimetics were prescribed (asthma: OR = 2.3; CI 1.2–4.2; COPD: OR = 4.1; CI 1.8–9.4). CONCLUSIONS: This study revealed that spirometry was used more often when corticosteroids or sympathomimetics were prescribed. The findings suggest that treatment was based on diagnostic test results rather than on recorded diagnoses. The documented ICD-10 codes may not always reflect the real status of the patients. Thus medical care for asthma and COPD in general practice may be better than initially found on the basis of recorded diagnoses, although further improvement of practice patterns in asthma and COPD is still necessary

Increased expression of the ubiquitin – proteasome pathway in murine myotubes by proteolysis-inducing factor (PIF) is associated with activation of the transcription factor NF-κB

Proteolysis-inducing factor (PIF), isolated from a cachexia-inducing murine tumour, has been shown to stimulate protein breakdown in C 2C12 myotubes. The effect was attenuated by the specific proteasome inhibitor lactacystin and there was an elevation of proteasome 'chymotrypsin-like' enzyme activity and expression of 205 proteasome α-subunits at concentrations of PIF between 2 and 16 nM. Higher concentrations of PIF had no effect. The action of PIF was attenuated by eicosapentaenoic acid (EPA) (50 μM). At a concentration of 4 nM, PIF induced a transient decrease in IκBα levels after 30 min incubation, while no effect was seen at 20 nM PIF. The level of IκBα, an NF-κB inhibitory protein, returned to normal after 60 min. Depletion of IκBα from the cytosol was not seen in myotubes pretreated with EPA, suggesting that the NF-κB/IκB complex was stabilised. At concentrations between 2 and 8 nM, PIF stimulated an increased nuclear migration of NF-κB, which was not seen in myotubes pretreated with EPA. The PIF-induced increase in chymotrypsin-like enzyme activity was also attenuated by the NF-κB inhibitor peptide SN50, suggesting that NF-κB may be involved in the PIF-induced increase in proteasome expression. The results further suggest that EPA may attenuate protein degradation induced by PIF, at least partly, by preventing NF-κB accumulation in the nucleus. © 2003 Cancer Research UK

Exhaled nitric oxide and urinary EPX levels in infants: a pilot study

<p>Abstract</p> <p>Background</p> <p>Objective markers of early airway inflammation in infants are not established but are of great interest in a scientific setting. Exhaled nitric oxide (FeNO) and urinary eosinophilic protein X (uEPX) are a two such interesting markers.</p> <p>Objective</p> <p>To investigate the feasibility of measuring FeNO and uEPX in infants and their mothers and to determine if any relations between these two variables and environmental factors can be seen in a small sample size. This was conducted as a pilot study for the ongoing Swedish Environmental Longitudinal Mother and child Asthma and allergy study (SELMA).</p> <p>Methods</p> <p>Consecutive infants between two and six months old and their mothers at children's health care centres were invited, and 110 mother-infant pairs participated. FeNO and uEPX were analysed in both mothers and infants. FeNO was analyzed in the mothers online by the use of the handheld Niox Mino device and in the infants offline from exhaled air sampled during tidal breathing. A 33-question multiple-choice questionnaire that dealt with symptoms of allergic disease, heredity, and housing characteristics was used.</p> <p>Results</p> <p>FeNO levels were reduced in infants with a history of upper respiratory symptoms during the previous two weeks (p < 0.002). There was a trend towards higher FeNO levels in infants with windowpane condensation in the home (p < 0.05). There was no association between uEPX in the infants and the other studied variables.</p> <p>Conclusion</p> <p>The use of uEPX as a marker of early inflammation was not supported. FeNO levels in infants were associated to windowpane condensation. Measuring FeNO by the present method may be an interesting way of evaluating early airway inflammation. In a major population study, however, the method is difficult to use, for practical reasons.</p

Role of protein kinase C and NF-κB in proteolysis-inducing factor-induced proteasome expression in C2C12 myotubes

Proteolysis-inducing factor (PIF) is a sulphated glycoprotein produced by cachexia-inducing tumours, which initiates muscle protein degradation through an increased expression of the ubiquitin–proteasome proteolytic pathway. The role of kinase C (PKC) in PIF-induced proteasome expression has been studied in murine myotubes as a surrogate model of skeletal muscle. Proteasome expression induced by PIF was attenuated by 4alpha-phorbol 12-myristate 13-acetate (100 nM) and by the PKC inhibitors Ro31-8220 (10 muM), staurosporine (300 nM), calphostin C (300 nM) and Gö 6976 (200 muM). Proteolysis-inducing factor-induced activation of PKCalpha, with translocation from the cytosol to the membrane at the same concentration as that inducing proteasome expression, and this effect was attenuated by calphostin C. Myotubes transfected with a constitutively active PKCalpha (pCO2) showed increased expression of proteasome activity, and a longer time course, compared with their wild-type counterparts. In contrast, myotubes transfected with a dominant-negative PKCalpha (pKS1), which showed no activation of PKCalpha in response to PIF, exhibited no increase in proteasome activity at any time point. Proteolysis-inducing factor-induced proteasome expression has been suggested to involve the transcription factor nuclear factor-kappaB (NF-kappaB), which may be activated through PKC. Proteolysis-inducing factor induced a decrease in cytosolic I-kappaBalpha and an increase in nuclear binding of NF-kappaB in pCO2, but not in pKS1, and the effect in wild-type cells was attenuated by calphostin C, confirming that it was mediated through PKC. This suggests that PKC may be involved in the phosphorylation and degradation of I-kappaBalpha, induced by PIF, necessary for the release of NF-kappaB from its inactive cytosolic complex

Research productivity and academics’ conceptions of research

This paper asks the question: do people with different levels of research productivity and identification as a researcher think of research differently? It discusses a study that differentiated levels of research productivity among English and Australian academics working in research-intensive environments in three broad discipline areas: science, engineering and technology; social science and humanities; and medicine and health sciences. The paper explores the different conceptions of research held by these academics in terms of their levels of research productivity, their levels of research training, whether they considered themselves an active researcher and a member of a research team, and their disciplinary differences

Expression of the ubiquitin-proteasome pathway and muscle loss in experimental cancer cachexia

Muscle protein degradation is thought to play a major role in muscle atrophy in cancer cachexia. To investigate the importance of the ubiquitin-proteasome pathway, which has been suggested to be the main degradative pathway mediating progressive protein loss in cachexia, the expression of mRNA for proteasome subunits C2 and C5 as well as the ubiquitin-conjugating enzyme, E214k, has been determined in gastrocnemius and pectoral muscles of mice bearing the MAC16 adenocarcinoma, using competitive quantitative reverse transcriptase polymerase chain reaction. Protein levels of proteasome subunits and E214k were determined by immunoblotting, to ensure changes in mRNA were reflected in changes in protein expression. Muscle weights correlated linearly with weight loss during the course of the study. There was a good correlation between expression of C2 and E214k mRNA and protein levels in gastrocnemius muscle with increases of 6–8-fold for C2 and two-fold for E214k between 12 and 20% weight loss, followed by a decrease in expression at weight losses of 25–27%, although loss of muscle protein continued. In contrast, expression of C5 mRNA only increased two-fold and was elevated similarly at all weight losses between 7.5 and 27%. Both proteasome functional activity, and proteasome-specific tyrosine release as a measure of total protein degradation was also maximal at 18–20% weight loss and decreased at higher weight loss. Proteasome expression in pectoral muscle followed a different pattern with increases in C2 and C5 and E214k mRNA only being seen at weight losses above 17%, although muscle loss increased progressively with increasing weight loss. These results suggest that activation of the ubiquitin-proteasome pathway plays a major role in protein loss in gastrocnemius muscle, up to 20% weight loss, but that other factors such as depression in protein synthesis may play a more important role at higher weight loss