Complete Sequences of Organelle Genomes from the Medicinal Plant Rhazya Stricta (Apocynaceae) and Contrasting Patterns of Mitochondrial Genome Evolution Across Asterids

Rhazya stricta is native to arid regions in South Asia and the Middle East and is used extensively in folk medicine to treat a wide range of diseases. In addition to generating genomic resources for this medicinally important plant, analyses of the complete plastid and mitochondrial genomes and a nuclear transcriptome from Rhazya provide insights into inter-compartmental transfers between genomes and the patterns of evolution among eight asterid mitochondrial genomes. Results: The 154,841 bp plastid genome is highly conserved with gene content and order identical to the ancestral organization of angiosperms. The 548,608 bp mitochondrial genome exhibits a number of phenomena including the presence of recombinogenic repeats that generate a multipartite organization, transferred DNA from the plastid and nuclear genomes, and bidirectional DNA transfers between the mitochondrion and the nucleus. The mitochondrial genes sdh3 and rps14 have been transferred to the nucleus and have acquired targeting presequences. In the case of rps14, two copies are present in the nucleus; only one has a mitochondrial targeting presequence and may be functional. Phylogenetic analyses of both nuclear and mitochondrial copies of rps14 across angiosperms suggests Rhazya has experienced a single transfer of this gene to the nucleus, followed by a duplication event. Furthermore, the phylogenetic distribution of gene losses and the high level of sequence divergence in targeting presequences suggest multiple, independent transfers of both sdh3 and rps14 across asterids. Comparative analyses of mitochondrial genomes of eight sequenced asterids indicates a complicated evolutionary history in this large angiosperm clade with considerable diversity in genome organization and size, repeat, gene and intron content, and amount of foreign DNA from the plastid and nuclear genomes. Conclusions: Organelle genomes of Rhazya stricta provide valuable information for improving the understanding of mitochondrial genome evolution among angiosperms. The genomic data have enabled a rigorous examination of the gene transfer events. Rhazya is unique among the eight sequenced asterids in the types of events that have shaped the evolution of its mitochondrial genome. Furthermore, the organelle genomes of R. stricta provide valuable genomic resources for utilizing this important medicinal plant in biotechnology applications.King Abdulaziz UniversityIntegrative Biolog

Impact of antibiotic usage on resistance in microorganisms; urinary tract infections with E-coli as a case in point

Objectives: In this study, we sought to establish a correlation between consumption of flouoroquinolones in our hospital and the emergence of ofloxacin resistant strains of E. coli in the urinary specimens. Data of all urinary samples, received at Aga Khan University Hospital between January 1995 and December 2002, was retrieved and analyzed. Specimens yielding E-coli as an isolate were included in this study. Methods: E. coli Isolates showing \u3e103 colonies were identified using standard microbiological techniques. Antibiotic susceptibility of E. coli was tested using Kirby Bauer disc diffusion method. Antimicrobial usage data, obtained through hospital Pharmacy as unit utilized per year for Quinolones in different medical and surgical units was available only for the period of 1997- 2002. Results: Among 32,722 urinary specimens E. coli (53%) was the most frequent isolate. Steady increase in the number of ofloxacin resistant E. coli was noted, 24% in 1995 to 55% in 2002. Maximum quinolone resistant E. coli have been observed in Medical units, 41% in 1997 increasing to 70% in 2002, followed by Surgery units (35% to 54%) and Pediatrics (12 to 38%). Sharp increase in ofloxacin consumption in our hospital, 1997 (28613 units) to 2002 (96880 units) has been observed. Trends in quinolone resistance correlate significantly with utilization in the same period as shown by linear regression. Conculsion: E. coli resistance against most antibiotics has been on a rise particularly for quinolones. The utilization of quinolones correlates with increasing resistance in our hospitalized patients

In vitro cytotoxic and antimicrobial effects of a novel peroxysesquiterpene glucoside from the rhizomes of Cyperus rotundus L (Cyperaceae)

Purpose: To study the antimicrobial and cytotoxic potential of a novel 3,9-peroxsesquiterpene-15-Oglucoside from Cyperus rotundus rhizomes, against HeLa cell line and selected strains of microorganisms. Methods: The rhizomes were macerated with methanol and fractionated with n-hexane, chloroform, ethyl acetate and butanol. High-performance liquid chromatography (HPLC) was performed together with chemical analysis of the fractions. The 3,9-peroxysesquiterpene-15-O-glucoside was purified through column chromatography of the ethyl acetate fraction, and its purity was determined via reversephase HPLC. Structural elucidation was done with Infrared (IR), proton-nuclear magnetic resonance (HNMR), carbon-13 nuclear magnetic resonance (13C NMR), and mass spectrometry (MS) spectroscopic analyses. Results: The isolated compound exhibited bactericidal and fungicidal activities against S. aureus and C. albicans at concentration, respectively, in the range of 32 – 100 μg/mL, while MTT assay results showed the cytotoxicity of the compound against eukaryotic (HeLa) cell line (IC50, 88.32 μg/mL). Conclusion: The isolated metabolite from the methanol extract of C. rotundus rhizome exhibits bactericidal, fungicidal, and cytotoxic potential. However, further studies are required to ascertain its suitability for use as a therapeutic agent. Keywords: Terpenoids, Column chromatography, Spectroscopy, Antimicrobial, Cytotoxicity, Cyperus rotundu

Morphological and biochemical variation in Sea buckthorn Hippophae rhamnoides ssp. turkestanica, a multipurpose plant for fragile mountains of Pakistan

Sea buckthorn (Hippophae rhamnoides ssp. turkestanica) a member of family Elaeagnaceae, is a very important multipurpose plant in the northern areas of Pakistan. It is an ideal plant for preventing soil erosion and land reclamation, can withstand extremes of temperature ranging from −43°C to 55°C and grows well under drought conditions and variable soil pH. The fruit is rich in nutrients and medicinal compounds such as vitamins, carotene, flavonoids, essential oil, carbohydrates, organic acids, amino acids, and soluble sugars. The plants are also important as fuel wood, fencing, fodder, soil erosion control, to make soil fertile by nitrogen fixation in roots and for the purpose of shelterbelts. In order to compare various populations of Sea buckthorn for morphological and biochemical composition, ten populations from different areas of northern Pakistan were compared using plant and fruit characters. The purpose of the investigation was to identify the variable populations for different valuable characteristics to develop improved varieties for commercial cultivation and easy fruit harvesting. The comparison indicated a significant amount of variability on morphological and biochemical basis. The variability will be utilised to develop commercial varieties of the plant utilising the conventional techniques of selection and hybridisation for economic activities on degraded land of mountainous regions of Pakistan

Alternans in Genetically Modified Langendorff-Perfused Murine Hearts Modeling Catecholaminergic Polymorphic Ventricular Tachycardia

The relationship between alternans and arrhythmogenicity was studied in genetically modified murine hearts modeling catecholaminergic polymorphic ventricular tachycardia (CPVT) during Langendorff perfusion, before and after treatment with catecholamines and a β-adrenergic antagonist. Heterozygous (RyR2p/s) and homozygous (RyR2s/s) RyR2-P2328S hearts, and wild-type (WT) controls, were studied before and after treatment with epinephrine (100 nM and 1 μM) and propranolol (100 nM). Monophasic action potential recordings demonstrated significantly greater incidences of arrhythmia in RyR2p/s and RyR2s/s hearts as compared to WTs. Arrhythmogenicity in RyR2s/s hearts was associated with alternans, particularly at short baseline cycle lengths. Both phenomena were significantly accentuated by treatment with epinephrine and significantly diminished by treatment with propranolol, in full agreement with clinical expectations. These changes took place, however, despite an absence of changes in mean action potential durations, ventricular effective refractory periods or restitution curve characteristics. Furthermore pooled data from all hearts in which arrhythmia occurred demonstrated significantly greater alternans magnitudes, but similar restitution curve slopes, to hearts that did not demonstrate arrhythmia. These findings thus further validate the RyR2-P2328S murine heart as a model for human CPVT, confirming an alternans phenotype in common with murine genetic models of the Brugada syndrome and the congenital long-QT syndrome type 3. In contrast to these latter similarities, however, this report demonstrates the dissociation of alternans from changes in the properties of restitution curves for the first time in a murine model of a human arrhythmic syndrome

Criteria for arrhythmogenicity in genetically-modified Langendorff-perfused murine hearts modelling the congenital long QT syndrome type 3 and the Brugada syndrome

The experiments investigated the applicability of two established criteria for arrhythmogenicity in Scn5a+/Δ and Scn5a+/− murine hearts modelling the congenital long QT syndrome type 3 (LQT3) and the Brugada syndrome (BrS). Monophasic action potentials (APs) recorded during extrasystolic stimulation procedures from Langendorff-perfused control hearts and hearts treated with flecainide (1 μM) or quinidine (1 or 10 μM) demonstrated that both agents were pro-arrhythmic in wild-type (WT) hearts, quinidine was pro-arrhythmic in Scn5a+/Δ hearts, and that flecainide was pro-arrhythmic whereas quinidine was anti-arrhythmic in Scn5a+/− hearts, confirming clinical findings. Statistical analysis confirmed a quadratic relationship between epicardial and endocardial AP durations (APDs) in WT control hearts. However, comparisons between plots of epicardial against endocardial APDs and this reference curve failed to correlate with arrhythmogenicity. Restitution curves, relating APD to diastolic interval (DI), were then constructed for the first time in a murine system and mono-exponential growth functions fitted to these curves. Significant (P < 0.05) alterations in the DI at which slopes equalled unity, an established indicator of arrhythmogenicity, now successfully predicted the presence or absence of arrhythmogenicity in all cases. We thus associate changes in the slopes of restitution curves with arrhythmogenicity in models of LQT3 and BrS

Development of a nanobiodegradable drilling fluid using prosopis farcta plant and pomegranate peel powders with metal oxide nanoparticles

One of the inevitable problems encountered during the petroleum well drilling process is lost circulation in which part of the drilling fluid is lost into the formation. A combination of nanoparticles with their unique properties and cost-effective biodegradable materials can play an effective role in treating fluid loss. In this study, our aim was to formulate drilling fluids modified with nanoparticles, pomegranate peel powder, and Prosopis farcta plant powder. The drilling fluids were identified and recognized using scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy techniques. Furthermore, experimental tests were conducted in order to investigate the performance of the newly formulated drilling fluid in improving fluid loss characteristics. The obtaining results have shown that adding 0.3 wt % of pomegranate peel powder to the reference (base) drilling fluid reduces the filter loss volume to 7.9 mL compared to the reference fluid (11.6 mL). As the optimal concentration of TiO2 was mixed with 0.3 wt % of pomegranate peel powder then added to the reference fluid, the filter loss volume was reduced to 8.6 mL