Stoichiometric investigations of laser-ablated brass plasma

Laser-ablated brass plasma plumes expanding in various air pressures have been studied using optical emission spectroscopy and two-dimensional imaging. The velocity of the plume front calculated from the R-t plot decreases from 1.9×10(4) m/s to ~5.5×10(3) m/s as the pressure increases from 0.01 to 10(5) Pa. The estimated higher electron temperature for Cu I (510.5 nm) transition than for Zn I (481.1 nm) may be due to differences in the heat of vaporization and vaporization temperature of copper and zinc. The electron density estimated using the Stark-broadened transition 4p(2)P(3/2)→4s(2)(2)D(5/2) of Cu I (510.5 nm) is about 10 times higher than that for transition 4s5s(3)S(1)→4s4p(3)P(2) of Zn I (481.1 nm). The appearance and enhancement of the Cu(2) (A-X) band at lower ambient pressure and formation of nanoparticle clusters have been extensively discussed. Stoichiometric and morphological study of the deposited nanoparticles on carbon tape at different ambient pressure reveals a different percentage composition of copper and of nanoparticles.

Alteration in mitochondrial thiol enhances calcium ion dependent membrane permeability transition and dysfunction in vitro: a cross-talk between mtThiol, Ca(2+), and ROS

Mitochondrial permeability transition (MPT) and dysfunctions play a pivotal role in many patho-physiological and toxicological conditions. The interplay of mitochondrial thiol (mtThiol), MPT, Ca(2+) homeostasis, and resulting dysfunctions still remains controversial despite studies by several research groups. Present study was undertaken to ascertain the correlation between Ca(2+) homeostasis, mtThiol alteration and reactive oxygen species (ROS) in causing MPT leading to mitochondrial dysfunction. mtThiol depletion significantly enhanced Ca(2+) dependent MPT (swelling) and depolarization of mitochondria resulting in release of pro-apoptotic proteins like Cyt c, AIF, and EndoG. mtThiol alteration and Ca(2+) overload caused reduced mitochondrial electron flow, oxidation of pyridine nucleotides (NAD(P)H) and significantly enhanced ROS generation (DHE and DCFH-DA fluorescence). Studies with MPT inhibitor (Cyclosporin A), Ca(2+) uniport blocker (ruthenium red) and Ca(2+) chelator (BAPTA) indicated that mitochondrial dysfunction was more pronounced under dual stress of altered mtThiol and Ca(2+) overload in comparison with single stress of excessive Ca(2+). Transmission electron microscopy confirmed the changes in mitochondrial integrity under stress. Our findings suggest that the Ca(2+) overload itself is not solely responsible for structural and functional impairment of mitochondria. A multi-factorial cross-talk between mtThiol, Ca(2+) and ROS is responsible for mitochondrial dysfunction. Furthermore, minor depletion of mtThiol was found to be an important factor along with Ca(2+) overload in triggering MPT in isolated mitochondria, tilting the balance towards disturbed functionality.

Nimesulide aggravates redox imbalance and calcium dependent mitochondrial permeability transition leading to dysfunction in vitro

Nimesulide (selective cyclooxygenase-2 inhibitor) is a nonsteroidal anti-inflammatory drug for the symptomatic treatment of painful conditions like osteoarthritis, spondilitis and primary dysmenorrhoea. Nimesulide induced liver damage is a serious side effect of this otherwise popular drug. The mechanism involved in nimesulide induced hepatotoxicity is still not fully elucidated. However, both mitochondrial dysfunction and oxidative stress have been implicated in contributing to liver injury in susceptible patients. Mitochondria besides being the primary source of energy, act as a hub of signals responsible for initiating cell death, irrespective of the pathway, i.e. apoptosis or necrosis. The present study was aimed to explore the role of compounding stress, i.e. Ca(2+) overload and GSH depletion in nimesulide induced mitochondrial toxicity and dysfunction. Our study showed that, nimesulide (100 microM) treatment resulted into rapid depletion of GSH (60%) in isolated rat liver mitochondria and significant Ca(2+) dependent MPT changed. Enhanced ROS generation (DCF fluorescence) was also observed in mitochondria treated with nimesulide. An important finding was that the concentration at which nimesulide oxidized reduced pyridine nucleotides (autofluorescence of NAD(P)H), it affected mitochondrial electron flow (MTT activity decreased by 75%) and enhanced mitochondrial depolarization significantly as assessed by Rhodamine 123 fluorescent probe. Therefore, nimesulide was found to aggravate redox imbalance and affect Ca(2+) dependent mitochondrial membrane permeability transition leading to dysfunction and ultimately cell death.

Acquired isolated unilateral fourth nerve palsy after ventriculoperitoneal shunt surgery

Ventriculoperitoneal shunt has been the surgical procedure of choice for many years for both communicating and noncommunicating hydrocephalus.(1) High failure rates and complications have been reported, despite major improvements in shunt technology(2); however, fourth (trochlear) nerve palsy has not been reported after this procedure. We describe 2 patients who developed a fourth nerve palsy after shunt surgery. Recovery was incomplete, and strabismus surgery was required.

Excyclotorsion in congenital fibrosis of extraocular muscles

The authors report marked bilateral excyclotorsion contributing to loss of binocularity and leading to ipsilateral head tilt in a patient with congenital fibrosis of the extraocular muscles type 1. Neuroimaging revealed bilateral hypoplastic superior recti and levator palpebrae superioris muscles. Postoperatively, head tilt was relieved and excyclotorsion was reduced. Assessment of torsion may influence surgical strategies and outcome in patients with congenital fibrosis of the extraocular muscles.

A New Begomovirus Species Causing Leaf Curl Disease of Radish in India

Leaf curl disease of radish (RLCD) was observed for the first time in India in commercial fields and kitchen gardens of the Varanasi District and adjoining areas of eastern Uttar Pradesh during November 2003. Infected plants exhibited typical upward and downward leaf curling, leaf distortion, reduction of leaf area, and conspicuous enations on the underside of the leaves. Incidence of RLCD was estimated to be between 10 and 40% depending on the cultivars used. Electron microscopic observation revealed typical geminate particles in infected leaf samples. The causal virus could be transmitted to radish cv. Minu Early by whiteflies (Bemisia tabaci) and grafting. Inoculated plants developed symptoms similar to those observed in naturally infected radish plants. Viral DNA was isolated from artificially inoculated symptomatic radish plants (4) followed by concentration of super-coiled DNA by alkaline denaturation (1). The presence of a geminivirus was confirmed by PCR using DNA-A degenerate primers (3), and a 1.5-kb amplified product was obtained from six artificially and three naturally infected plants. Amplification of the full-length DNA-A was achieved using a primer combination derived from sequences obtained from a 1.5-kb amplicon. Amplification of 1.3-kb DNA-β sequences was achieved using specific primers (2) in three infected plants. Sequence analysis revealed that DNA-A (GenBank Accession No. EF 175733) contained 2,756 nt and DNA-β contained 1,358 nt (GenBank Accession No. EF 175734). DNA-A of the causal virus shares 87.7% identity with Tomato leaf curl Bangladesh virus (GenBank Accession No. AF 188481) and 62% identity with Mungbean yellow mosaic India virus (GenBank Accession No. AF126406). The begomovirus DNA-A sequence associated with RLCD contained seven open reading frames (AV1, AV2, AC1, AC2, AC3, AC4, and AC5). The DNA-β associated with RLCD shared the highest nucleotide sequence identity (84.9%) with DNA-β of Tobacco leaf curl virus isolate NIB 12-1 (GenBank Accession No. AJ316033) reported from Pakistan. Despite exhaustive attempts to amplify a putative viral B-component using degenerate primers based on the intergenic region sequence of the DNA-A or sequences that are highly conserved for other begomoviruses, no DNA-B component was detected. On the basis of DNA-A sequence analysis, the ICTV species demarcation criteria of 89% sequence identity, and genome organization, the virus causing RLCD should be considered a new Begomovirus species, for which the name Radish leaf curl virus (RLCV) is proposed. To our knowledge, this is the first report of the association of a Begomovirus with a disease of radishes in India. References: (1) H. C. Birnboim and J. Doly. Nucleic Acids Res. 7:1513, 1979. (2) R. W. Briddon et al. Mol. Biotechnol. 20:315, 2002. (3) M. R. Rojas et al. Plant Dis. 77:340, 1993. (4) K. M. Srivastava et al. J. Virol. Methods 51:297, 1995.

Characterization of nanostructured PZT prepared by chemical routes

Nanostructured, crystalline Pb(Zr0.52Ti0.48)O3 (crystallite size 8-10 nm) ceramic powders were synthesized at low temperature by the hydroxide co-precipitation and aqueous solution method (water bath technique). The phase and surface morphology characterizations were carried out by XRD, SEM, and TEM analyses. XRD powder pattern exhibited the presence of a major tetragonal and a minor rhombohedral crystalline phase indicating the mixed phase composition in both the samples. SEM-EDS analysis revealed good homogeneity of the materials. From evolution of the Raman spectra the spectroscopic signature of the corresponding phases was determined. Detailed dielectric measurements (between 30 degrees C to 500 degrees C) were obtained to analyze a complete set of impedance-related functions such as dielectric constant (epsilon), loss factor (tan delta), dielectric modulus (M), and conductivity (sigma). Similar to the normal ferroelectric (FE) materials, the dielectric constant (epsilon) of synthesized PZTs was found to be increasing gradually with temperature and attains a maxima (epsilonmax) at the Curie temperature (Tc). The peaks in the dielectric constant plots are attributed to the phase transition associated with the change from tetragonal to rhombohedral structures. The higher dielectric constant of the PZT prepared by hydroxide co-precipitation make it more suitable for various applications.

Bilateral incyclotorsion, absent facial nerve, and anotia: fellow travelers in Möbius sequence or oculoauriculovertebral spectrum?

We report a patient with bilateral incyclotorsion, asymmetric facial palsy, monocular depression deficiency, and unilateral Type 3 Duane syndrome, along with contralateral anotia and a midline cleft palate. A dysplastic middle ear cavity and unilateral absence of the facial nerve were noted on magnetic resonance imaging scanning. The differential diagnosis includes Möbius sequence, oculoauriculovertebral spectrum, and a congenital cranial dysinnervation disorder.

Arsenic contamination in the Kanker district of central-east India: geology and health effects

This paper identifies newer areas of arsenic contamination in the District Kanker, which adjoins the District Rajnandgaon where high contamination has been reported earlier. A correlation with the mobile phase episodes of arsenic contamination has been identified, which further hinges on the complex geology of the area. Arsenic concentrations in both surface and groundwater, aquatic organisms (snail and water weeds) soil and vegetation of Kanker district and its adjoining area have been reported here. The region has been found to contain an elevated level of arsenic. All segments of the ecoysystem are contaminated with arsenic at varying degrees. The levels of arsenic vary constantly depending on the season and location. An analysis of groundwater from 89 locations in the Kanker district has shown high values of arsenic, iron and manganese (mean: 144, 914 and 371 microg L(-1), respectively). The surface water of the region shows elevated levels of arsenic, which is influenced by the geological mineralised zonation. The most prevalent species in the groundwater is As(III), whereas the surface water of the rivers shows a significant contamination with the As(V) species. The analysis shows a bio-concentration of the toxic metals arsenic, nickel, copper and chromium. Higher arsenic concentrations (groundwater concentrations greater than 50 microg L(-1)) are associated with sedimentary deposits derived from volcanic rocks, hence mineral leaching appears to be the source of arsenic contamination. Higher levels of arsenic and manganese in the Kanker district have been found to cause impacts on the flora and fauna. A case study of episodic arsenical diarrhoea is presented.

Cloning, restriction mapping and phylogenetic relationship of genomic components of MYMIV from Lablab purpureus

The present work describes cloning of genomic components of whitefly transmitted geminivirus infecting Lablab purpureus syn. Dolichos lablab (commonly known as Dolichos bean or Hyacinth bean). The genome characterization using PCR with geminiviral degenerate primers and DNA sequencing were used to describe the bipartite virus associated with yellow mosaic disease of Dolichos lablab. Full-length DNA-A and DNA-B clones were obtained. The DNA-A sequence analysis showed that the isolate was similar to other Mungbean yellow mosaic India virus (MYMIV) isolates reported earlier. The nucleotide sequence analysis of the full-length DNA-A of virus isolate revealed more than 97% homology with Mungbean yellow mosaic India virus-[Cowpea] (AF481865), while the DNA-B also showed >95% homology with MYMIV-[Cp] (AF503580) and MYMIV-[Sb] (AY049771). The phylogenetic analysis of present isolate showed close relationship to legume geminiviruses. The nucleotide sequence analysis showed presence of six open reading frames (ORFs) in DNA-A, with 2 ORFs aligned in sense and 4 ORFs in antisense orientation. Similarly, DNA-B contained two open reading frames (ORFs), one in sense and another in antisense orientation.

Amniotic membrane transplantation versus mucous membrane grafting in anophthalmic contracted socket

PURPOSE

Amniotic membrane has been successfully used for treatment of various ocular surface disorders, but there have been no published reports untill now regarding its use in the treatment of contracted socket. The aim of this study was to determine the role of amniotic membrane and to compare the results with mucous membrane grafting in anophthalmic contracted socket.

METHODS

A prospective study of 20 eyes with mild to moderate anophthalmic contracted socket was carried out. Two groups, each with 10 eyes, were formed randomly. Group A underwent amniotic membrane transplantation, and Group B mucous membrane grafting. Prosthesis was fitted 6-8 weeks post operatively. The volume and fornices' length was compared preoperatively and at 3, 6 and 12 months postoperatively.

RESULTS

Apart from measurements, patient satisfaction was an important criteria in defining the success of the procedure. At the end of 12 months, the relative increase between the 2 groups in the fornix and volume measurements were statistically significant (SF-0.001,IF-0.001,V-0.001) with better patient comfort in group A. There was no statistical significance regarding the rate of complications between both the groups (p = 0.29).

CONCLUSION

Amniotic membrane emerges as a viable alternative to established mucous membrane grafting as it causes less patient morbidity, faster recovery and better fitting of prosthesis. No contracture is observed with amniotic membrane as against mucous membrane. It is cheap and easily available and has no significant complications associated with it.

Simultaneous Intraocular and Bilateral Extraocular Muscle Involvement in a Case of Disseminated Cysticercosis

We report an unusual case of disseminated cysticercosis having simultaneous intraocular and extraocular involvement. This 21-year-old male presented with recent loss of vision in one eye and history of a single seizure. Examination revealed intravitreal cysticercosis with exudative retinal detachment. Computed tomographic scan showed disseminated neurocysticercosis and cysticercosis of the medial and inferior recti of both the eyes. The patient was started on albendazole and prednisolone under neurologist's supervision. Subsequent computed tomographic scan showed resolution of the extraocular muscle cysts and decrease in the number of neurocysticerci. The patient has had no further seizures. This is the first report of simultaneous intraocular and extraocular cysticercosis.

Canine tooth syndrome due to superior oblique myocysticercosis

A 13-year-old boy had right periocular pain, upgaze vertical diplopia, and lid swelling. Right extorsion and hypodense cystic swelling in the right superior oblique involving the muscle and tendon behind the trochlea existed. Oral treatment was prescribed. MRI revealed a collapsed cyst. Ocular motility improved, but levoelevation diplopia persisted.

Removal of arsenic(III) from aqueous solutions using fresh and immobilized plant biomass

The ability of Garcinia cambogia, an indigenous plant found in many parts of India, to remove trivalent arsenic from solution was assessed. Batch experiments were carried out to characterize the As(III) removal capability of fresh and immobilized biomass of G. cambogia. It was found that the kinetic property and uptake capacity of fresh biomass were significantly enhanced by the immobilization procedure. The uptake of As(III) by fresh and immobilized biomass was not greatly affected by solution pH with optimal biosorption occurring at around pH 6--8. The presence of common ions such as Ca and Mg at concentrations up to 100mg/l had no effect on As(III) removal. However, the presence of Fe(III) at 100mg/l caused a noticeable drop in the extent of As(III) removal but the effect was minimal when Fe(III) was present at 10mg/l. The adsorption isotherms quantitatively predicted the extent of As(III) removal in groundwater samples collected from an arsenic-contaminated site in India. Immobilized biomass loaded with As(III) was amenable to efficient regeneration with NaOH solution. Column studies showed that immobilized biomass could be reused over five cycles of loading and elution. The excellent As(III) sequestering capability of fresh and immobilized G. cambogia biomass could lead to the development of a viable and cost-effective technology for arsenic removal in groundwater.

Tomato leaf curl Gujarat virus, a New Begomovirus Species Causing a Severe Leaf Curl Disease of Tomato in Varanasi, India

ABSTRACT The biological and molecular properties of Tomato leaf curl Gujarat virus from Varanasi, India (ToLCGV-[Var]) were characterized. ToLCGV-[Var] could be transmitted by grafting and through whitefly transmission in a persistent manner. The full-length genome of DNA-A and DNA-B of ToLCGV-[Var] was cloned in pUC18. Sequence analysis revealed that DNA-A (AY190290) is 2,757 bp and DNA-B (AY190291) is 2,688 bp in length. ToLCGV-[Var] could infect and cause symptoms in tomato, pepper, Nicotiana benthamiana, and N. tabacum when partial tandem dimeric constructs of DNA-A and DNA-B were co-inoculated by particle bombardment. DNA-A alone also is infectious, but symptoms were milder and took longer to develop. ToLCGV-Var virus can be transmitted through sap inoculation from infected tomato plants to the above-mentioned hosts causing the same symptoms. Open reading frames (ORFs) in both DNA-A and DNA-B are organized similarly to those in other begomoviruses. DNA-A and DNA-B share a common region of 155 bp with only 60% sequence identity. DNA-B of ToLCGV-[Var] shares overall 80% identity with DNA-B of Tomato leaf curl New Delhi virus-Severe (ToLCNDV-Svr) and 75% with ToLCNDV-[Lucknow] (ToLCNDV-[Luc]). Comparison of DNA-A sequence with different begomoviruses indicates that ToLCGV-[Var] shares 84% identity with Tomato leaf curl Karnataka virus (ToLCKV) and 66% with ToLCNDV-Svr. ToLCGV-[Var] shares a maximum of 98% identity with another isolate of the same region (ToLCGV-[Mir]; AF449999) and 97% identity with one isolate from Gujarat (ToLCGV-[Vad]; AF413671). All three viruses belong to the same species that is distinct from all the other geminivirus species described so far in the genus Begomovirus of the family Geminiviridae. The name Tomato leaf curl Gujarat virus is proposed because the first sequence was taken from an isolate of Gujarat, India.