Esterification of 2-methylalkanoic acids Catalysed by Lipase from Candida rugosa: Enantioselectivity as a Function of water Activity and Alcohol Chain Length

Esterifications catalysed by immobilised lipase from Candida rugosa (CRL) in cyclohexane at constant water activity (a_w = 0.76) were studied using 2-methyl substituted octa-, nona- or decanoic acids and n-alcohols of varying chain length as substrates. The importance of controlling the water activity and choosing the right alcohol for obtaining maximum enantioselectivity is demonstrated. The immobilised lipase was easily recovered without loss of activity and enantioselectivity.     

Individual and combined effects of DNA methylation and copy number alterations on miRNA expression in breast tumors

Background

The global effect of copy number and epigenetic alterations on miRNA expression in cancer is poorly understood. In the present study, we integrate genome-wide DNA methylation, copy number and miRNA expression and identify genetic mechanisms underlying miRNA dysregulation in breast cancer.

Results

We identify 70 miRNAs whose expression was associated with alterations in copy number or methylation, or both. Among these, five miRNA families are represented. Interestingly, the members of these families are encoded on different chromosomes and are complementarily altered by gain or hypomethylation across the patients. In an independent breast cancer cohort of 123 patients, 41 of the 70 miRNAs were confirmed with respect to aberration pattern and association to expression. In vitro functional experiments were performed in breast cancer cell lines with miRNA mimics to evaluate the phenotype of the replicated miRNAs. let-7e-3p, which in tumors is found associated with hypermethylation, is shown to induce apoptosis and reduce cell viability, and low let-7e-3p expression is associated with poorer prognosis. The overexpression of three other miRNAs associated with copy number gain, miR-21-3p, miR-148b-3p and miR-151a-5p, increases proliferation of breast cancer cell lines. In addition, miR-151a-5p enhances the levels of phosphorylated AKT protein.

Conclusions

Our data provide novel evidence of the mechanisms behind miRNA dysregulation in breast cancer. The study contributes to the understanding of how methylation and copy number alterations influence miRNA expression, emphasizing miRNA functionality through redundant encoding, and suggests novel miRNAs important in breast cancer.     

Atlantic cod actively avoid CO<Subscript>2</Subscript> and predator odour,even after long-term CO<Subscript>2</Subscript> exposure

Introduction

The rising atmospheric CO₂ level is continuously driving the dissolution of more CO₂ into the oceans, and some emission scenarios project that the surface waters may reach 1000 μatm by the end of the century. It is not known if fish can detect moderately elevated CO₂ levels, and if they avoid areas with high CO₂. If so, avoidance behaviour to water with high CO₂ could affect movement patterns and migrations of fish in the future. It is also being increasingly recognized that fish behaviour can be altered by exposure to CO₂. Therefore this study investigated how long-term exposure to elevated pCO₂ affects predator avoidance and CO₂ avoidance in juvenile Atlantic cod (Gadus morhua). The fish were exposed to control water or CO₂-enriched water (1000 μatm) for six weeks before being subjected to tests of behaviour.

Results

Despite long term exposure to elevated pCO₂ the cod still strongly avoided the smell of a predator. These data are surprising because several coral reef fish have demonstrated reversal of olfactory responses after CO₂ exposure, turning avoidance of predator cues into preference for predator cues. Fish from both treatment groups also demonstrated strong avoidance of CO₂ when presented with the choice of control or CO₂-acidified water, indicating that habituation to the CO₂ sensory stimuli is negligible.

Conclusions

As Atlantic cod maintained normal behavioural responses to olfactory cues, they may be tolerant to CO₂-induced behavioural changes. The results also suggest that despite the long-term exposure to CO₂-acidified water, the fish still preferred the control water over CO₂-acidified water. Therefore, in the future, fish may alter their movements and migrations in search of waters with a lower CO₂ content.

     

Canine Mammary Tumours Are Affected by Frequent Copy Number Aberrations,including Amplification of MYC and Loss of PTEN

BackgroundCopy number aberrations frequently occur during the development of many cancers. Such events affect dosage of involved genes and may cause further genomic instability and progression of cancer. In this survey, canine SNP microarrays were used to study 117 canine mammary tumours from 69 dogs.ResultsWe found a high occurrence of copy number aberrations in canine mammary tumours, losses being more frequent than gains. Increased frequency of aberrations and loss of heterozygosity were positively correlated with increased malignancy in terms of histopathological diagnosis. One of the most highly recurrently amplified regions harbored the MYC gene. PTEN was located to a frequently lost region and also homozygously deleted in five tumours. Thus, deregulation of these genes due to copy number aberrations appears to be an important event in canine mammary tumour development. Other potential contributors to canine mammary tumour pathogenesis are COL9A3, INPP5A, CYP2E1 and RB1. The present study also shows that a more detailed analysis of chromosomal aberrations associated with histopathological parameters may aid in identifying specific genes associated with canine mammary tumour progression.ConclusionsThe high frequency of copy number aberrations is a prominent feature of canine mammary tumours as seen in other canine and human cancers. Our findings share several features with corresponding studies in human breast tumours and strengthen the dog as a suitable model organism for this disease.     

Chronic meningitis and Lyme disease in Sweden.

We studied 35 patients with chronic meningitis. The neurological abnormalities included aseptic meningitis, cranial neuropathy (mostly facial palsy), motor and sensory peripheral radiculoneuropathy, and myelitis. Neurological symptoms were sometimes preceded by erythema chronicum migrans or an insect bite and were often accompanied by fever, malaise, profound fatigue, and weight loss. The cerebrospinal fluid (CSF) abnormalities consisted of a predominantly mononuclear pleocytosis, an elevated CSF protein (mean 2.3 g/l), intrathecal synthesis of oligoclonal immunoglobulin G, and, in half of the patients, a fall in the CSF/blood glucose ratio. High antibody titers to the Lyme spirochete and the Swedish Ixodes ricinus spirochete were demonstrated by immunofluorescence in 26 of the 35 patients. By imprint immunofixation of electrofocused samples of serum and CSF, intrathecal production of oligoclonal Lyme-spirochete-specific IgG was demonstrated in one patient with chronic meningitis. Four sequential paired samples of serum and CSF from this patient showed local synthesis of spirochete-specific antibodies in CSF. The 35 patients improved or recovered, sometimes dramatically, during a two-week course of intravenous penicillin G.     

Barriers and challenges in clinical ethics consultations: the experiences of nine clinical ethics committees

Clinical ethics committees have recently been established in nearly all Norwegian hospital trusts. One important task for these committees is clinical ethics consultations. This qualitative study explores significant barriers confronting the ethics committees in providing such consultation services. The interviews with the committees indicate that there is a substantial need for clinical ethics support services and, in general, the committee members expressed a great deal of enthusiasm for the committee work. They also reported, however, that tendencies to evade moral disagreement, conflict, and 'outsiders' are common in the hospitals. Sometimes even the committees comply with some of these tendencies. The committees agree that there is a need to improve their routines and procedures, clarify the committees' profile and field of responsibility, to make the committees well-known, to secure adequate operating conditions, and to develop organizational integration and support. Various strategies to meet these challenges on a local, regional or national level are also explored in this paper.     

Psoriasis: familial predisposition and environmental factors.

In a survey for coronary risk factors 14 667 adult men and women answered a questionnaire on lifestyle, diet, and health, including whether they had psoriasis. The overall prevalence of psoriasis was 4.79% in men and 4.85% in women. The data showed an increasing incidence of psoriasis. The association with family history, lifestyle, diet, and health was explored by multiple regression analysis. The occurrence of psoriasis in first degree relatives contributed to more than 90% of the explained variance for both sexes. Of the other variables, only the positive association with rheumatoid arthritis was significant in both sexes. It is concluded that the examined environmental factors have only minor effects on the prevalence of psoriasis.     

Trypsin IV or mesotrypsin and p23 cleave protease-activated receptors 1 and 2 to induce inflammation and hyperalgesia

Although principally produced by the pancreas to degrade dietary proteins in the intestine, trypsins are also expressed in the nervous system and in epithelial tissues, where they have diverse actions that could be mediated by protease-activated receptors (PARs). We examined the biological actions of human trypsin IV (or mesotrypsin) and rat p23, inhibitor-resistant forms of trypsin. The zymogens trypsinogen IV and pro-p23 were expressed in Escherichia coli and purified to apparent homogeneity. Enteropeptidase cleaved both zymogens, liberating active trypsin IV and p23, which were resistant to soybean trypsin inhibitor and aprotinin. Trypsin IV cleaved N-terminal fragments of PAR(1), PAR(2), and PAR(4) at sites that would expose the tethered ligand (PAR(1) = PAR(4) > PAR(2)). Trypsin IV increased [Ca(2+)](i) in transfected cells expressing human PAR(1) and PAR(2) with similar potencies (PAR(1), 0.5 microm; PAR(2), 0.6 microm). p23 also cleaved fragments of PAR(1) and PAR(2) and signaled to cells expressing these receptors. Trypsin IV and p23 increased [Ca(2+)](i) in rat dorsal root ganglion neurons that responded to capsaicin and which thus mediate neurogenic inflammation and nociception. Intraplantar injection of trypsin IV and p23 in mice induced edema and granulocyte infiltration, which were not observed in PAR (-/-)(1)(trypsin IV) and PAR (-/-)(2) (trypsin IV and p23) mice. Trypsin IV and p23 caused thermal hyperalgesia and mechanical allodynia and hyperalgesia in mice, and these effects were absent in PAR (-/-)(2) mice but maintained in PAR (-/-)(1) mice. Thus, trypsin IV and p23 are inhibitor-resistant trypsins that can cleave and activate PARs, causing PAR(1)- and PAR(2)-dependent inflammation and PAR(2)-dependent hyperalgesia.     

Richness dependence and climatic forcing as regulating processes of coastal fish-species richness

The maintenance of species diversity is influenced by processes originating both within and outside the ecological community of concern. Along the Norwegian Skagerrak coast, the number of fish species displays variability around a rather stable long‐time average. Using a mechanistically based first‐order autoregressive model with environmental forcing for the species number, we demonstrate for this system the presence of richness‐dependent regulation of species diversity. We explicitly model the niche space as a carrying capacity of species diversity and the intrinsic community feedback as a richness‐dependent regulation. Wind stress, temperature and the North Atlantic Oscillation (NAO) are used as environmental variables. This general and flexible model successfully captures the community dynamics of fish in the coastal areas of the Norwegian Skagerrak coast and thereby demonstrates the validity of developing general models of biodiversity patterns.