The Egyptian Cardiothoracic Surgeon (ECTS - E-Journal)
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Functional analysis of N-linking oligosaccharyl transferase enzymes encoded by deep-sea vent proteobacteria.
No full textBacterial N-linking oligosaccharyl transferases (OTase enzymes) transfer lipid-linked glycans to selected proteins in the periplasm and were first described in the intestinal pathogen Campylobacter jejuni, a member of the ϵ-proteobacteria-subdivision of bacteria. More recently, orthologues from other ϵ-proteobacterial Campylobacter and Helicobacter species and a δ-proteobacterium, Desulfovibrio desulfuricans, have been described, suggesting that these two subdivisions of bacteria may be a source of further N-linked protein glycosylation systems. Whole-genome sequencing of both ϵ- and δ-proteobacteria from deep-sea vent habitats, a rich source of species from these subdivisions, revealed putative ORFs encoding OTase enzymes and associated adjacent glycosyltransferases similar to the C. jejuni N-linked glycosylation locus. We expressed putative OTase ORFs from the deep-sea vent species Nitratiruptor tergarcus, Sulfurovum lithotrophicum and Deferribacter desulfuricans in Escherichia coli and showed they were able to functionally complement the C. jejuni OTase, CjPglB . The enzymes were shown to possess relaxed glycan specificity, transferring diverse glycan structures and demonstrated different glycosylation sequon specificities. Additionally a permissive D. desulfuricans acceptor protein was identified, and we provide evidence that the N-linked glycan synthesised by N. tergarcus and S. lithotrophicum contains an acetylated sugar at the reducing end. This work demonstrates that deep-sea vent bacteria encode functional N-glycosylation machineries and are a potential source of biotechnologically important OTase enzymes
Assessing the environmental sustainability of energy recovery from municipal solid waste in the UK
No full textA dim view of M-cone onsets
No full textWe investigated the brightness (i.e., perceived luminance) of isolated L- and M-cone pulses to seek a perceptual correlate of our previous reports that M-on electroretinograms resemble L-off responses, implying the operationof post-receptoral opponent processing. Using triple silent substitutions, cone increments were generated in a 4-primary ganzfeld, masked by random positive or negative luminance bias. The results show that M-coneincrements decrease in brightness, while L-cone increments increase. These differences became smaller as field size reduced; this was not eccentricity or area dependent. We speculate about early retinal input into brightnessperception
Individual variation in whole-animal hypoxia tolerance is associated with cardiac hypoxia tolerance in a marine teleost
No full textHypoxia is a pervasive problem in coastal environments and is predicted to have enduring impacts on aquatic ecosystems. Intraspecific variation in hypoxia tolerance is well documented in fish; however, the factors underlying this variation remain unknown. Here, we investigate the role of the heart in individual hypoxia tolerance of the European sea bass (Dicentrarchus labrax). We found individual whole-animal hypoxia tolerance is a stable trait in sea bass for more than 18 months (duration of study). We next examined in vitro cardiac performance and found myocardial muscle from hypoxia-tolerant individuals generated greater force, with higher rates of contraction and relaxation, than hypoxic-sensitive individuals during hypoxic exposure. Thus, whole-animal hypoxia tolerance is associated with cardiac hypoxia tolerance. As the occurrence of aquatic hypoxia is expected to increase in marine ecosystems, our experimental data suggest that cardiac performance may influence fish survival and distribution
Hormone replacement therapy after treatment for a gynaecological malignancy
No full textPURPOSE OF REVIEW: Provision of hormone replacement therapy (HRT) to women following a diagnosis of a gynaecological malignancy is a complex and controversial area associated with a lack of published guidance. As the average age of women affected by gynaecological cancer decreases and survival following provision of effective therapies increases, clinicians face new considerations for longer-term health concerns of patients. Additionally, there is a growing understanding of the influence of tumour biology upon response to cytotoxic therapies and it is essential that we use this knowledge to guide provision of HRT. RECENT FINDINGS: Available evidence for ovarian, vulval, cervical, and endometrial cancers demonstrates no excess risk of recurrence in patients taking HRT with the exception of some subtypes of cancer (uterine sarcomas, granulosa cell, and low-grade serous ovarian cancer). Evidence for the incidence of hormone receptor status is suggestive that HRT may be ill-advised in an additional proportion of patients and we recommend characterization of all tumours in patients who may require HRT. SUMMARY: The risk and benefits of HRT should be evaluated for all women who undergo a premature menopause as a result of gynaecological malignancy to reduce menopausal symptoms and protect against cardiovascular and skeletal morbidity. There is no evidence to suggest a higher rate of disease recurrence in women using HRT in comparison to nonusers in the majority of gynaecological malignancies. Routine histological testing of tumours for hormone receptor status is an achievable goal and may help to stratify patients further into low and high-risk groups for hormone therapy
A new role of Nod proteins in regulation of intestinal goblet cell response in the context of innate host defense in an enteric parasite infection
No full textMucins secreted by intestinal goblet cells are considered as an important component of innate defense in a number of enteric infections, including many parasitic infections, but also likely provide protection against the gut microbiota. Nod proteins are intracellular receptors that play key roles in innate immune response and inflammation. Herein we investigated the role of Nod proteins in regulation of intestinal goblet cell response in naïve and enteric parasite, Trichuris muris-infected mice. We observed significantly fewer periodic acid Schiff (PAS)-stained intestinal goblet cells and mucin (Muc2) in Nod1 and Nod2 double knockout (Nod DKO) mice after T. muris infection as compared to the wild-type (WT) mice. Expulsion of parasites from the intestine was significantly delayed in Nod DKO mice. Treatment of naïve WT mice with Nod1 and Nod2 agonists simultaneously increased PAS-stained goblet cells numbers and Muc2 expressing cells whereas treatment with Nod1 or Nod 2 separately had no significant effect. Stimulation of mucin-secreting LS174T cells with Nod1 and Nod2 agonists up-regulated core 3 β1,3-N-acetylglucosaminyltransferase (C3GnT; an important enzyme in mucin synthesis) and MUC2 . We also observed lower PAS-stained goblet cell numbers and Muc2 in germ-free mice. Treatment with Nod1 and Nod2 agonists enhanced the numbers of PAS stained-goblet cells and Muc2 production in germ-free mice. These data provide novel information on the role of Nod proteins in goblet cell response and Muc2 production in relation to intestinal innate defense
The effects of corporate acquisitions on CEO compensation and CEO turnover of family firms
No full textThis paper investigates the impact of corporate acquisitions on CEO compensation and CEO turnover of family firms in Continental Europe. We find that CEOs in family firms do not experience an increase in their compensation during the post-acquisition period, while there is a positive and statistically significant association between the compensation of CEOs in non-family firms and their acquisition activity. This finding is consistent with the view that controlling family shareholders provide monitoring for CEOs mitigating managerial agency problems that arise from the separation of ownership and control. Further, we find that the likelihood of CEO turnover declines following an acquisition in non-family firms, suggesting that these acquiring CEOs do not face a higher likelihood of dismissal while they receive a higher level of compensation. In contrast, there is no significant impact of acquisitions on CEO turnover in family firms
Collectives' and Individuals' Duties: A Parity Argument
No full textIndividuals have various kinds of obligations: keep promises, don’t cause harm, return benefits received from injustices, be partial to loved ones, help the needy, and so on. How does this work for group agents? There are two questions here. The first is whether groups can bear the same kinds of obligations as individuals. The second is whether groups’ pro tanto obligations plug into what they all-things-considered ought to do to the same degree that individuals’ pro tanto obligations plug into what they all-things-considered ought to do. We argue for parity on both counts