Single lesion multibacillary leprosy, a treatment enigma: a case report

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Insight into the Assembly Properties and Functional Organisation of the Magnetotactic Bacterial Actin-like Homolog, MamK

Magnetotactic bacteria (MTB) synthesize magnetosomes, which are intracellular vesicles comprising a magnetic particle. A series of magnetosomes arrange themselves in chains to form a magnetic dipole that enables the cell to orient itself along the Earth’s magnetic field. MamK, an actin-like homolog of MreB has been identified as a central component in this organisation. Gene deletion, fluorescence microscopy and in vitro studies have yielded mechanistic differences in the filament assembly of MamK with other bacterial cytoskeletal proteins within the cell. With little or no information on the structural and behavioural characteristics of MamK outside the cell, the mamK gene from Magnetospirillium gryphiswaldense was cloned and expressed to better understand the differences in the cytoskeletal properties with its bacterial homologues MreB and acitin. Despite the low sequence identity shared between MamK and MreB (22%) and actin (18%), the behaviour of MamK monitored by light scattering broadly mirrored that of its bacterial cousin MreB primarily in terms of its pH, salt, divalent metal-ion and temperature dependency. The broad size variability of MamK filaments revealed by light scattering studies was supported by transmission electron microscopy (TEM) imaging. Filament morphology however, indicated that MamK conformed to linearly orientated filaments that appeared to be distinctly dissimilar compared to MreB suggesting functional differences between these homologues. The presence of a nucleotide binding domain common to actin-like proteins was demonstrated by its ability to function both as an ATPase and GTPase. Circular dichroism and structural homology modelling showed that MamK adopts a protein fold that is consistent with the ‘classical’ actin family architecture but with notable structural differences within the smaller domains, the active site region and the overall surface electrostatic potential

Analysis of Phosphate Acquisition Efficiency in Different Arabidopsis Accessions

The morphological and physiological characteristics of Arabidopsis accessions differing in their phosphate acquisition efficiencies (PAEs) when grown on a sparingly soluble phosphate source (hydroxylapatite) were analyzed. A set of 36 accessions was subjected to an initial PAE evaluation following cultivation on synthetic, agarose-solidified media containing potassium phosphate (soluble) or hydroxylapatite (sparingly soluble). From the five most divergent accessions identified in this way, C24, Co, and Cal exhibited high PAEs, whereas Col-0 and Te exhibited low PAEs. These five accessions were analyzed in detail. Significant differences were found in root morphology, phosphate uptake kinetics, organic acid release, rhizosphere acidification, and the ability of roots to penetrate substrates. Long root hairs at high densities, high uptake per unit root length, and high substrate penetration ability in the efficient accessions C24 and Co mediate their high PAEs. The third accession with high PAE, Cal, exhibits a high shoot-to-root ratio, long roots with long root hairs, and rhizosphere acidification. These results are consistent with previous observations and highlight the suitability of using Arabidopsis accessions to identify and isolate genes determining the PAE in plants

Pharmaceutical dosage forms and drug delivery

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N-Salicoylhydrazine & N,N'-Disalicoylhydrazine Complexes of Cu(II), Ni(II), Co(II), Fe(II) & Mn(II)

364-36

Frequency doubled Nd :YAG (532 nm) laser photocoagulation in corneal vascularisation : efficacy and time sequenced changes.

PURPOSE: To evaluate the efficacy of frequency-doubled Nd:YAG (532 nm) laser treatment in quiescent corneal vascularisation, and to record the sequential changes in lasered vessels and complications in eyes with one and two quadrant vascularisation. METHODS: Thirty eyes (30 patients)--15 eyes (15 patients) with one-quadrant and 15 eyes (15 patients) with two-quadrant corneal vascularisation were treated. Frequency-doubled Nd:YAG laser (532 nm) was used at laser setting of 120-480 mw power, 50-150 mm spot size and 0.05 sec pulse duration. The area of corneal vascularisation, status of treated corneal vessels, area of corneal opacity and visual acuity were recorded before treatment, at one week after treatment and thereafter at monthly intervals up to three months. RESULTS: The mean area of corneal vascularisation decreased from 20.09% to 8.31% of the total corneal area in group I (p<0.01) and from 44.34% to 20.67% of the total corneal area in group II (p<0.01) at 3 months′ follow-up. The mean reduction in the area of corneal vascularisation was 58.64% in group I and 53.38% in group II (p>0.05). Of 148 corneal vessels treated, 60 (44.6%) were totally occluded, 44 (30%) partially occluded, 37 (28%) recanalized and there was one shunt vessel at one week following laser treatment. At three months′ follow-up, 80 (54.15%) vessels were totally occluded, 14 (9%) partially occluded, 52 (35.14%) recanalised and two shunt vessels appeared. Thus, at three months′ follow-up, the number of totally occluded vessels increased and partially occluded vessels decreased. Superficial corneal haemorrhage was observed in 4 (14%) patients. CONCLUSION: Frequency-doubled Nd:YAG (532 nm) laser photocoagulation appears a safe and effective means of reducing the area of corneal vascularisation in quiescent eyes with vascularised corneal opacities