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41.
Evolution of the Adh locus in the Drosophila willistoni group: the loss of an intron, and shift in codon usage 总被引:1,自引:0,他引:1
We report here the DNA sequence of the alcohol dehydrogenase gene (Adh)
cloned from Drosophila willistoni. The three major findings are as follows:
(1) Relative to all other Adh genes known from Drosophila, D. willistoni
Adh has the last intron precisely deleted; PCR directly from total genomic
DNA indicates that the deletion exists in all members of the willistoni
group but not in any other group, including the closely related saltans
group. Otherwise the structure and predicted protein are very similar to
those of other species. (2) There is a significant shift in codon usage,
especially compared with that in D. melanogaster Adh. The most striking
shift is from C to U in the wobble position (both third and first
position). Unlike the codon-usage-bias pattern typical of highly biased
genes in D. melanogaster, including Adh, D. willistoni has nearly 50% G + C
in the third position. (3) The phylogenetic information provided by this
new sequence is in agreement with almost all other molecular and
morphological data, in placing the obscura group closer to the melanogaster
group, with the willistoni group farther distant but still clearly within
the subgenus Sophophora.
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42.
An exception to the generally conservative nature of plastid gene evolution
is the gene coding for the beta" subunit of RNA polymerase, rpoC2. Previous
work by others has shown that maize and rice have an insertion in the
coding region of rpoC2, relative to spinach and tobacco. To assess the
distribution of this extra coding sequence, we surveyed a broad
phylogenetic sample comprising 55 species from 17 angiosperm families by
using Southern hybridization. The extra coding sequence is restricted to
the grasses (Poaceae). DNA sequence analysis of 11 species from all five
subfamilies within the grass family demonstrates that the extra sequence in
the coding region of rpoC2 is a repetitive array that exhibits more than a
twofold increase in nucleotide substitution, as well as a large number of
insertion/deletion events, relative to the adjacent flanking sequences. The
structure of the array suggests that slipped-strand mispairing causes the
repeated motifs and adds to the mechanisms through which the coding
sequence of plastid genes are known to evolve. Phylogenetic analyses based
on the sequence data from grass species support several relationships
previously suggested by morphological work, but they are ambiguous about
broad relationships within the family.
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43.
Background
The Burkholderia cepacia complex (Bcc) is a collection of nine genotypically distinct but phenotypically similar species. They show wide ecological diversity and include species that are used for promoting plant growth and bio-control as well species that are opportunistic pathogens of vulnerable patients. Over recent years the Bcc have emerged as problematic pathogens of the CF lung. Pseudomonas aeruginosa is another important CF pathogen. It is able to synthesise hydrogen cyanide (HCN), a potent inhibitor of cellular respiration. We have recently shown that HCN production by P. aeruginosa may have a role in CF pathogenesis. This paper describes an investigation of the ability of bacteria of the Bcc to make HCN. 相似文献44.
Kumar Narayanan Mohammed Omer Mohammed Arif Papani Sridhar Nitin Annarapu Shivaprasad Naidu Pankaj Jariwala Narasaraju Kavalipati Mukharjee Madivada Ramagiri Balaji Premchand M Sharath Reddy A Anil Krishna G Padmakumar EA 《Indian pacing and electrophysiology journal》2021,21(1):5-10
BackgroundLeft-sided ablation, targeting left inferior AV nodal extensions, is thought to be necessary for success in a small proportion of atrioventricular nodal re-entrant tachycardia (AVNRT) ablations; however Indian data are scarce in this regard.MethodsConsecutive cases of AVNRT undergoing slow pathway ablation in a single centre over an 18-month period were retrospectively analyzed. Left-sided ablation at the posteroseptal mitral annulus was performed if right-sided ablation failed to abolish AVNRT.ResultsFrom January 2017 to June 2018, out of 215 consecutive supraventricular tachycardia (SVT) cases, 154 (71.6%) were AVNRT (47.1 ± 13.1 years, 46.1% male). Trans-septal ablation was required in 5 (3.2%) cases (mean age 48.8 ± 9.4 years; 4 female, 1 male); all with typical (slow-fast) form of AVNRT. Compared with cases needing only right-sided ablation, radiofrequency time (50.8 ± 16.9 vs. 9.9 ± 8.5 min; p = 0.005) and procedure time (166.0 ± 35.0 vs 79.6 ± 35.9 min; p = 0.004) were significantly longer for trans-septal cases, while baseline intervals and tachycardia cycle length were not significantly different. Junctional ectopy was seen in only 2 of the 5 cases during left-sided ablation, but acute success (non-inducibility) was obtained in 3 cases. There were no instances of AV block. Over mean follow-up of 12.2 ± 4.0 months, clinical recurrence of AVNRT occurred in one case, while others remained arrhythmia-free without medication.ConclusionLeft-sided ablation was required in a small proportion of AVNRT ablations. Trans-septal approach targeting the posteroseptal mitral annulus was safe and yielded good mid-term clinical success. 相似文献
45.
Jo?o B. A. Neto Cecília R. da Silva Maria A. S. Neta Rosana S. Campos Janaína T. Siebra Rose A. C. Silva Danielle M. Gaspar Hemerson I. F. Magalh?es Manoel O. de Moraes Marina D. P. Lobo Thalles B. Grangeiro Tatiane S. C. Carvalho Emilay B. T. Diogo Eufranio N. da Silva Júnior Felipe A. R. Rodrigues Bruno C. Cavalcanti Hélio V. N. Júnior 《PloS one》2014,9(5)
In recent decades, the incidence of candidemia in tertiary hospitals worldwide has substantially increased. These infections are a major cause of morbidity and mortality; in addition, they prolong hospital stays and raise the costs associated with treatment. Studies have reported a significant increase in infections by non-albicans Candida species, especially C. tropicalis. The number of antifungal drugs on the market is small in comparison to the number of antibacterial agents available. The limited number of treatment options, coupled with the increasing frequency of cross-resistance, makes it necessary to develop new therapeutic strategies. The objective of this study was to evaluate and compare the antifungal activities of three semisynthetic naphthofuranquinone molecules against fluconazole-resistant Candida spp. strains. These results allowed to us to evaluate the antifungal effects of three naphthofuranquinones on fluconazole-resistant C. tropicalis. The toxicity of these compounds was manifested as increased intracellular ROS, which resulted in membrane damage and changes in cell size/granularity, mitochondrial membrane depolarization, and DNA damage (including oxidation and strand breakage). In conclusion, the tested naphthofuranquinones (compounds 1–3) exhibited in vitro cytotoxicity against fluconazole-resistant Candida spp. strains. 相似文献
46.
Floris EA Udink ten Cate Nathalie Wiesner Uwe Trieschmann Markus Khalil Narayanswami Sreeram 《Indian pacing and electrophysiology journal》2010,10(6):248-256
A subset of children and adults with Wolff-Parkinson-White (WPW) syndrome develop dilated cardiomyopathy (DCM). Although DCM may occur in symptomatic WPW patients with sustained tachyarrhythmias, emerging evidence suggests that significant left ventricular dysfunction may arise in WPW in the absence of incessant tachyarrhythmias. An invariable electrophysiological feature in this non-tachyarrhythmia type of DCM is the presence of a right-sided septal or paraseptal accessory pathway. It is thought that premature ventricular activation over these accessory pathways induces septal wall motion abnormalities and ventricular dyssynchrony. LV dyssynchrony induces cellular and structural ventricular remodelling, which may have detrimental effects on cardiac performance. This review summarizes recent evidence for development of DCM in asymptomatic patients with WPW, discusses its pathogenesis, clinical presentation, management and treatment. The prognosis of accessory pathway-induced DCM is excellent. LV dysfunction reverses following catheter ablation of the accessory pathway, suggesting an association between DCM and ventricular preexcitation. Accessory pathway-induced DCM should be suspected in all patients presenting with heart failure and overt ventricular preexcitation, in whom no cause for their DCM can be found. 相似文献
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