Hydrogen sulphide alleviates cadmium stress in Trigonella foenum-graecum by modulating antioxidant enzymes and polyamine content

Cadmium (Cd) toxicity reduces growth and yield of crops grown in metal-polluted sites. Research was conducted to estimate the potential of hydrogen sulphide (H₂ S) to mitigate toxicity caused by Cd in fenugreek seedlings (Trigonella foenum-graecum L.). Different concentrations of CdCl₂ (Cd1-1 mM, Cd2-1.5 mM, Cd3-2mM) and H₂ S (HS1-100 µM, HS2-150 µM, HS3-200 µM) were assessed. Seeds of fenugreek were primed with sodium hydrosulphide (NaHS), as H₂ S donor. Seedlings growing in Cd-spiked media treated with H₂ S were harvested after 2 weeks. Cd stress affected growth of fenugreek seedlings. Cd toxicity decreased leaf relative water content (LRWC), intercellular CO₂ concentration, net photosynthesis, stomatal conductance and transpiration. However, application of H₂ S significantly improved seedling morphological attributes by increasing the activity of antioxidant enzymes, i.e. APX, CAT and SOD, in Cd-contaminated soil. H₂ S treatment also regulated phenolic and flavonoid content. H₂ S-induced biosynthesis of spermidine (Spd) and putrescine (Put) could account for the enhancement of growth and physiological performance of fenugreek seedlings under Cd stress. H₂ S treatment also reduced H₂ O₂ production (38%) and electrolyte leakage (EL, 51%) in seedlings grown in different concentrations of Cd. It is recommended to evaluate the efficacy of H₂ S in alleviating Cd toxicity in other crop plants.

Clinical Scenario and Imaging with Illustrations of Giant Cell Tumor of Bone: A Retrospective Analysis

BACKGROUND

The giant cell tumour of the bone has a spectrum of clinical-radiological presentation. This study aims to describe this varied presentation in our institution.

METHODS

This retrospective study was conducted on twenty-nine pathologically labelled cases of giant cell tumours of the bone. The medical records for their clinical presentation and diagnostic imaging studies were studied and evaluated.

RESULTS

Mean age of the patients at presentation was 35.3±12.9 years. Pain, local swelling and restricted joint function were seen in 93 %, 58.6 % and 52 % patients, respectively. The cortical breach was seen in 15 (51.7 %) and 22 (75.9 %) lesions on plain radiographs and CT images, respectively. 14(48.3 %) cases had soft tissue invasion on MRI at presentation. 26 (89.7 %) lesions were located within 1 cm from the articular cartilage. The solid tumour component was hypo to iso-intense in signal intensity in 27 (93.1 %) lesions in T1 weighted and 21 (72.4 %) in T2 weighted images. 14 (48.3 %) had hyperintense cystic areas, and fluid-fluid levels, suggestive of aneurysmal bone cysts, were seen in 4 (13.8 %) cases on T2 weighted images. Hypo-echoic nodular areas in solid tumour component, suggestive of hemosiderin deposits, were present in 3 (10.3 %) lesions on T1 and T2 weighted images.

CONCLUSION

The tumour classically presents as an epiphysial-metaphyseal, eccentric, expansile, lytic lesion in a skeletally mature patient. The MRI picture is variable and the surgeon should have a sound knowledge of these variations to obtain a biopsy sample from a proper site of the lesion and to avoid misdiagnosis especially of a primary ABC.

Traditional knowledge about medicinal plant in the remote areas of Wari Tehsil, Dir Upper, Pakistan

Traditional medicine is cheaper and easily available to local people, to care for most frequent diseases in the Northern parts of Pakistan. Our study aimed at inventorying medicine from local plants, documenting their uses, and assessing their market value in 2015-2018 during spring, summer, and winter seasons. A total of 15 trips were made, 5 in each season. Semi-structured interviews with 165 inhabitant's age range between 20-80 years were conducted, analyzed the data is analyzed using Relative frequency of citation(RFC), Use Value(UV), Fidelity Level(FL), Informants consensus factor(ICF), and Jaccard index(JI) to find the most frequent and well-known used species in the area. A total of 86 species belonging to 39 vascular plant families, 33 genera were documented as medicinally important. Family Asteraceae was observed as the dominant family among all the families with 10 species, the leaf was the most used parts and decoction 36% was the most preferred preparation type. Herb was the predominant life form (67%). The maximum UV (0.92) was demonstrated by J. adhatoda L. species, while A. sativum L. shows maximum RFC (0.58), the highest ICF value represented by diarrhea and dermatitis 0.92, and high FL value is recorded 100%. According to our collections, wild species were 45%, invasive species were 38% and cultivated 17% recorded, dicots species were recorded more 81%. Seven 7 medicinal species is being economically important and export to the local and international market of the world, whereas P. integrima L. species were the most exported species according to the local dealers. The investigated area is rural and the local people depend on the area's plants for their health needs, and other uses like a vegetable, fuelwood, fodder, etc. The current result of RFC, UV, ICF, FL, and JI shows that medicinal flora needs to be pharmacologically and phytochemically investigated to prove their efficacy. The documentation of medicinal knowledge is important to preserve this precious old knowledge before it is lost forever, due to technological and environmental changes in the world.

Feral dogs in Chitral gol national park, Pakistan: a potential threat to the future of threatened Kashmir Markhor (Capra falconeri cashmiriensis)

Feral dogs are well-organized hunters of ungulates in many parts of the world, causing great damage to wildlife populations and ultimately to the ecosystem. In Pakistan, the impacts of feral dogs on the wildlife have not been documented yet. In a period of fifteen years (2006-2020), feral dogs have killed hundreds of threatened markhor in Chitral gol national park (CGNP), Pakistan. Despite direct predation other impacts including disturbance and competition with other natural predators, could compromise conservation and management efforts. The population of feral dogs seems to have been increased with the increase of dumping sites by communities. Our findings suggest that there are pressing needs of controlling the feral dogs population and eradicating them from the core zone of CGNP and surrounding buffer communities. Conventional culling of dogs should be coupled with modern techniques like castration and sterilization. Communities should be educated regarding the clean environment, proper disposal of home wastes and, biodiversity conservation.

PM-Scl and Th/To in systemic sclerosis: a comparison of different autoantibody assays

OBJECTIVE

To compare test characteristics of the Euroimmun line blot assay with other assays for two uncommon autoantibody specificities in systemic sclerosis (SSc).

METHODS

Patients from the Johns Hopkins Scleroderma Center were assayed routinely using the Euroimmun platform. Patients positive for anti-Th/To (N = 73) and anti-PM-Scl (PM75 and/or PM100; N = 290) by Euroimmun were compared with SSc patients negative for these autoantibodies. For Th/To antibodies, the comparison assay was immunoprecipitation (IP), performed using 4 Th/To complex components: POP1, RPP40, RPP30, and RPP25. For anti-PM-Scl, IPs were performed with PM100 and PM75. Different Euroimmun cut-offs for assigning antibody positive status (≥ 15/+, ≥ 36/++, ≥ 71/+++) were examined. Kappa statistics were calculated to determine agreement between assays.

RESULTS

The best performing thresholds for defining anti-PM-Scl positivity were both PM75 and PM100 ≥ 15/+ on Euroimmun, corresponding to a kappa statistic of 0.79, sensitivity 72% and specificity 100%. For anti-Th/To, kappa values were lower for all comparisons (κ < 0.5). Given the high sensitivity of defining anti-Th/To by ≥ 15/+ (91-95%), a potential approach is to use Euroimmun screening (15/+ cut-off), followed by confirmatory IP.

CONCLUSION

Given the increasing utilization of Euroimmun and the importance of comparing data across cohorts, continued use of this platform is warranted, acknowledging discordance with IP for some specificities. For these, using a two-step approach (Euroimmun to maximize sensitivity, confirmatory assay to increase specificity) is suggested.

KEY POINTS

• For less common SSc autoantibody specificities, some discordances exist between IP and Euroimmun LIA. • The best performing thresholds for defining anti-PM-Scl positivity were both PM75 and PM100 ≥ 15/+ on Euroimmun. • For Th/To, a two-step approach (Euroimmun to maximize sensitivity, confirmatory assay to increase specificity) is suggested.

Polyester-based biodegradable plastics: an approach towards sustainable development

Non-degradability of conventional plastics, filling of landfill sites, raising water and land pollution and rapid depletion of fossil resources have raised the environmental issues and global concerns. The current demand and production of plastics is putting immense pressure on fossil resources, consuming about 6% of the global oil and is expected to grow up to 20%. The polyester-based biodegradable plastics (BPs) are considered as a remedy to the issue of plastics waste in the environment. BPs appear to manage the overflow of plastics by providing new means of waste management system and help in securing the non-renewable resources of nature. This review comprehensively presents the environmental burdens due to conventional plastics as well as production of polyester-based BPs as an alternative to conventional commodity plastics. The diversity of micro-organisms and their enzymes that degrade various polyester-based BPs (PLA, PCL, PHB/PHBV and PET) has also been described in detail. Moreover, the impact of plastics degradation products on soil ecology and ecosystem functions has critically been discussed. The report ends with special focus on future recommendations for the development of sustainable waste management strategies to control pollution due to plastics waste. SIGNIFICANCE AND IMPACT OF THE STUDY: Polyester-based BPs considered as a solution to current plastic waste problem as well as leading polymers in terms of biodegradability and sustainability has been critically discussed. The role of microorganisms and their enzymes involved in the biodegradation of these polymers and ecotoxicological impact of degradation products of BPs on soil microbial community and biogeochemical cycles has also been described. This report will provide an insight on the key research areas to bridge the gap for development of simulated systems as an effective and emerging strategy to divert the overflow of plastic in the environment as well as for the greener solution to the plastic waste management problems.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

Ret Signaling Is Required for Tooth Pulp Innervation during Organogenesis

During organogenesis, the timing and patterning of dental pulp innervation require both chemoattractive and chemorepellent cues for precise spatiotemporal regulation. Our understanding of the signaling mechanisms that regulate tooth innervation during development, as well as the basic biology of these sensory neurons, remains rudimentary. In this study, we analyzed the expression and function of glial cell line-derived neurotrophic factor (GDNF) and its receptor tyrosine kinase, Ret, in the regulation of innervation of the mouse tooth pulp by dental pulpal afferent (DPA) neurons of the trigeminal ganglion (TG). Using reporter mouse models, we demonstrate that Ret is highly expressed by a subpopulation of DPA neurons projecting to the tooth pulp at both postnatal day 7 (P7) and in the adult. In the adult tooth, GDNF is highly expressed by many cell types throughout the dental pulp. Using a ubiquitous tamoxifen (TMX)-inducible Cre ( UBC-Cre/ER^T2) line crossed to Ret conditional knockout mice ( Ret^fx/fx), Ret was deleted immediately prior to tooth innervation, and the neural projections into P7 molars were analyzed. TMX treatment was efficient in ablating >95% of Ret protein. We observed that UBC-Cre/ER^T2; Ret^fx/fx mice had a significant reduction in the total number of neurites present within the pulp at P7, with a significant accumulation of aberrant fibers in the dental follicle and periodontium. In agreement with these findings, inhibition of Ret signaling through in vivo administration of a highly specific pharmacologic inhibitor (1NM-PP1) of Ret also caused a substantial reduction in pulpal innervation. Taken together, these findings indicate that Ret signaling regulates the timing and patterning of tooth innervation by dental primary afferent neurons of the TG during organogenesis and provide a rationale to explore whether alterations in the GDNF-Ret pathway contribute to pathophysiological conditions in the adult dentition.

A Surrogate Modelling Approach Based on Nonlinear Dimension Reduction for Uncertainty Quantification in Groundwater Flow Models

In this paper, we develop a surrogate modelling approach for capturing the output field (e.g. the pressure head) from groundwater flow models involving a stochastic input field (e.g. the hydraulic conductivity). We use a Karhunen–Loève expansion for a log-normally distributed input field and apply manifold learning (local tangent space alignment) to perform Gaussian process Bayesian inference using Hamiltonian Monte Carlo in an abstract feature space, yielding outputs for arbitrary unseen inputs. We also develop a framework for forward uncertainty quantification in such problems, including analytical approximations of the mean of the marginalized distribution (with respect to the inputs). To sample from the distribution, we present Monte Carlo approach. Two examples are presented to demonstrate the accuracy of our approach: a Darcy flow model with contaminant transport in 2-d and a Richards equation model in 3-d.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.

Ectoine: a compatible solute in radio-halophilic Stenotrophomonas sp. WMA-LM19 strain to prevent ultraviolet-induced protein damage

AIM

Thiss study was conducted to investigate the possible role of a compatible solute from radio-halophilic bacterium against desiccation and ultra-violet radiation-induced oxidative stress.

METHODS AND RESULTS

Nine different radio-resistant bacteria were isolated from desert soil, where strain WMA-LM19 was chosen for detailed studies on the basis of its high tolerance to ultraviolet radiation among all these isolates. Here, 16S rRNA gene sequencing indicated the bacterium was closely related to Stenotrophomonas sp. (KT008383). A bacterial milking strategy was applied for extraction of intracellular compatible solutes in 70% (v/v) ethanol, which were purified by High Performance Liquid Chromatography (HPLC). The compound was characterized as ectoine by ¹ H and ¹³ C Nuclear Magnetic Resonance (NMR), and Mass Spectrometry (MS). Ectoine inhibited oxidative damage to proteins and lipids in comparison to the standard ascorbic acid. It also demonstrated more efficient prevention (54·80%) against lysis to erythrocytes membrane by surface active agents than lecithin. Furthermore, a high level of ectoine-mediated protection of bovine serum albumin against ionizing radiation (1 500-2 000Jm^-2 ) was observed, as indicated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis.

CONCLUSION

The results indicated that ectoine from Stenotrophomonas sp. WMA-LM19 can be used as a potential mitigator and radio-protective agent to overcome radiation- and salinity-mediated oxidative damages in extreme environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

Due to its anti-oxidant properties, ectoine from a radio-halophilic bacterium might be used in sunscreen formulation for protection against UV-induced oxidative stress.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_{GW}(f=25  Hz)=1.8_{-1.3}^{+2.7}×10^{-9} with 90% confidence, compared with Ω_{GW}(f=25  Hz)=1.1_{-0.7}^{+1.2}×10^{-9} from binary black holes alone. Assuming the most probable rate for compact binary mergers, we find that the total background may be detectable with a signal-to-noise-ratio of 3 after 40 months of total observation time, based on the expected timeline for Advanced LIGO and Virgo to reach their design sensitivity.

First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

Effect of lactic acid bacteria-treated King grass silage on the performance traits and serum metabolites in New Zealand white rabbits (Oryctolagus cuniculus)

This study examined the effects of Lactobacillus plantarum and Pediococcus acidilactici-treated silage of King grass (Pennisetum purpureophoides) on the productive traits and blood biochemistry of New Zealand white (NZW) rabbits. King grass was ensiled without or with L. plantarum (T1), P. acidilactici (T2) and P. acidilactici + L. plantarum (T3). A total of 72 male NZW rabbits (6 weeks) of similar weight and appearance were housed in groups in metallic cages in a completely randomized design. The performance traits, daily feed intake, body weight gain and feed convention ratio were not affected by the silage treatment. Triglyceride and alanine aminotransferase (ALT) concentration was increased (p < .05) in T2 (0.92 mmol/L) compared to the other treatments. The superoxide dismutase (SOD), phosphorous (P) and magnesium (Mg) increased (p < .05) in T1 (658.01 nmol/ml, 5.1 mg/kg and 2.43 mg/kg, respectively) compared to the control and other experimental groups. Cu and Mn decreased (p < .05), while Zn increased (p < .05) in the treated groups compared to the control. The CP decreased (p < .05) in the treatment groups compared to the control. Neutral detergent fibre (NDF) increased (p < .05) in T2 (54.40%) compared to the other treatments. The inoculation of lactic acid bacteria-treated King grass silage supplementation positively affected rabbit performance and improved blood cholesterol profile, antioxidant status and improve nutrients digestibility.

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4}  years. We infer the component masses of the binary to be between 0.86 and 2.26  M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60  M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28  deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8}  Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Reduced-order modelling of parameter-dependent, linear and nonlinear dynamic partial differential equation models

In this paper, we develop reduced-order models for dynamic, parameter-dependent, linear and nonlinear partial differential equations using proper orthogonal decomposition (POD). The main challenges are to accurately and efficiently approximate the POD bases for new parameter values and, in the case of nonlinear problems, to efficiently handle the nonlinear terms. We use a Bayesian nonlinear regression approach to learn the snapshots of the solutions and the nonlinearities for new parameter values. Computational efficiency is ensured by using manifold learning to perform the emulation in a low-dimensional space. The accuracy of the method is demonstrated on a linear and a nonlinear example, with comparisons with a global basis approach.

Prognostic factors and 5-year survival of patients with carcinoma penis: Tertiary health center study

CONTEXT

To identify prognostic factors in carcinoma penis with its impact on survival.

AIMS

To find out the relation of various prognostic factors of carcinoma penis with the various outcomes.

SETTINGS AND DESIGN

Retrospective cohort study.

SUBJECTS AND METHODS

Each patient diagnosed as having carcinoma of penis by incision biopsy and operated from January 2004 to May 2009 at the institute was included in the study (n = 117). Data were collected and analyzed.

STATISTICAL ANALYSIS USED

The Chi-square (χ2) test was used to test for the significance of association between the independent (predictor) and dependent (outcome) variables. Multivariate logistic regression analysis was used to determine predictor variables that predicted the outcome. Five year disease-free survival (DFS) and overall survival (OS) were calculated using the Kaplan-Meier method.

RESULTS

Of the total 117 patients studied, 30 patients died within 5 years (median = 25 months). Recurrences (local or systemic) were seen in 23 patients (median = 14 months). Five-year DFS was 80.34% and OS was 72.22%. Kaplan-Meier analysis showed that well to moderately differentiated grade, lymph node negative disease and low stage have higher survivals than poorly differentiated grade, lymph node positive disease and higher stage, respectively. Multiple logistic regression analysis revealed that inguinal lymph node positivity and grade were significantly associated with local or systemic recurrence.

CONCLUSIONS

Penile cancer patients with advanced disease had poor survival. Tumor grade and inguinal lymph node metastasis are factors affecting DFS. Lymphadenectomy remains an integral part of the management of patients with penile cancer.

Incidence and outcomes of ventral hernia repair after robotic retropubic prostatectomy: A retrospective cohort of 570 consecutive cases

BACKGROUND

Robotic retropubic prostatectomy (RRP) has become one of the most commonly performed robotic procedures in the United States. Ventral hernia (VH) has been increasingly recognized as an important complication after laparoscopic procedures, in general. However, data related to VH after robotic procedures is relatively scarce, especially after RRP. With increasing popularity of RRP, the purpose of this study was to look at the incidence of VH and outcomes of ventral hernia repair (VHR) after RRP.

METHODS

All patients who underwent RRP at a single institution between January 2012 and June 2014 were studied retrospectively using electronic medical records.

RESULTS

A total of 570 patients underwent RRP, of which 33 (5.8%) developed VH during the study period. Fourteen (42%) patients were obese and five (15%) had diabetes. One patient (3%) had a surgical site infection after RRP and two (6%) patients were on immunomodulators/steroids. Median duration to develop VH after RRP was 12 (1-25) months. Out of the 33 patients with VH, ten (33%) underwent VHR; five laparoscopic and five open. Median size of hernia defect and mesh used was 25 (1-144) cm² and 181 (15-285) cm², respectively. Median length of hospital stay and follow up was 0 (0-4) days and 12 (1-14) months, respectively. One patient who had initial VHR done at an outside institution had a recurrence. Thirty-two (97%) patients were alive at their last follow up. One patient died secondary to progression of prostate cancer. There was no significant 30 day morbidity (surgical site infection, fascial dehiscence, pneumonia, acute kidney injury, myocardial infarction). Of patients who decided non-operative management of VH (n = 23, 67%), none developed a complication requiring emergent surgical intervention.

CONCLUSION

The incidence of VH after RRP is likely underreported in prior studies. Repair, either laparoscopic or open, is safe and effective in experienced hands. Patients who decide on watchful waiting can be followed with minimal risk of incarceration/strangulation. Further studies are needed to analyze the extraction techniques after RRP and correlate with incidence of VH.

Flooding adds pathogenic Escherichia coli strains to the water sources in southern Khyber Pakhtunkhwa, Pakistan

PURPOSE

Seasonal rains in Pakistan result in heavy floods across the country, whereby faecal contaminants will be added to the water bodies and cause numerous food-borne outbreaks. The present study was aimed to determine the prevalence of diarrheagenic Escherichia coli (DEC) strains in the water sources.

MATERIALS AND METHODS

Two hundred water samples collected during (2011-2012) were processed for the isolation of E. coli (EC) strains. EC strains were further analysed for antibiotic susceptibility patterns, and pathogroups-specific virulence factors stx1, stx2, stx2c, eae, tir, hlyA, bfpA, estA and eltA were detected using multiplex polymerase chain reaction.

RESULTS

Thirty-three percent of the water samples were contaminated with EC pathotypes. Fifty percent (33/66) of the DEC pathotypes were identified as enterotoxigenic EC (ETEC). Seventy-two percent (13/18) of the enteropathogenic EC (EPEC) strains were identified as typical EPEC and 28% (5/18) as atypical EPEC. Eleven percent (7/66) of the Shiga toxin EC (STEC) isolates carried a combination of stx1 and stx2 genes. Summer was found as a peak season with 47% (31/66) for EC pathogroups' activities. Eighty-nine percent of the strains showed resistance against tetracycline.

CONCLUSION

ETEC and EPEC are the primary causes of water contamination in southern regions of Khyber Pakhtunkhwa province, Pakistan. Firm adherence to the prescribed drugs can decrease trends in antibiotic resistance.

The difficult gall bladder: Outcomes following laparoscopic cholecystectomy and the need for open conversion

INTRODUCTION

Surgery for the difficult gallbladder (DGB) is associated with increased risk compared to more routine laparoscopic cholecystectomies (LC). Laparoscopic "damage control" methods including cholecystostomy, fundus-down approach and subtotal cholecystectomy (SC) have been proposed to avoid conversion to open. We hypothesized that a Total LC (TLC) for DBG can be completed safely with an acceptably low conversion rate.

MATERIAL AND METHODS

All patients that underwent LC from January 2005-June 2015 were retrospectively reviewed. Cases met criteria for DGB if they were necrotic/gangrenous, involved Mirizzi syndrome, had extensive adhesions, were converted to open, lasted more than 120 min, had prior tube cholecystostomy or known GB perforation.

RESULTS

A total of 2212 patients underwent LC during the study time period, of which 351 (15.8%) met criteria for DGB. Of these cases, 213 (60.7%) were admitted from the emergency department and 67 (19.1%) underwent urgent/emergent cholecystectomy (within 24 h). Additionally 18 (5.1%) had pre-operative tube cholecystostomies. Seventy patients (19.9%) were converted to open. Indications for conversion included severe inflammation/adhesion (n = 31, 46.3%), difficult anatomy (n = 14, 20.9%) and bleeding (n = 6, 9.0%). Predictors for conversion included urgent/emergent intervention (OR, 0.80; 95% CI 0.351-0.881, p = 0.032), previous abdominal surgery (OR, 2.18; 95% CI, 1.181-4.035, p = 0.013) and necrotic/gangrenous cholecystitis (OR, 1.92; 95% CI, 1.356-4.044, p = 0.033). Comparing the TLC and the conversion groups, mean operative time and length of hospital stay were significantly different; 147 ± 47 min vs 185 ± 71 min; p < 0.005 and 3 ± 2 days vs 5 ± 3 days; p = 0.011, respectively. There was no significant difference in postoperative hemorrhage, subhepatic collection, cystic duct leak, wound infection, reoperation and 30 day mortality. There was no bile duct injury in either group.

CONCLUSION

Total laparoscopic cholecystectomy can be safely performed in difficult gallbladder situations with a lower conversion rate than previously reported. Possible predictors of conversion include urgency, necrotic gallbladder and history of prior abdominal surgeries. For patients converted to open, similar morbidity and mortality can be expected.

Outcome of pregnancies complicated by systemic sclerosis and mixed connective tissue disease

Systemic sclerosis (SSc) and mixed connective tissue disease (MCTD) are rare autoimmune diseases which share the common feature of non-inflammatory vasculopathy. Studies evaluating pregnancy outcomes in these patients have yielded conflicting results. We sought to describe the outcomes of pregnancies associated with SSc and MCTD followed at our center utilizing a retrospective review of all pregnant women with SSc and MCTD followed at Stanford University from 1993 to 2003.

We identified 20 pregnancies occurring in 13 women with SSc or MCTD. Twelve pregnancies occurred in seven women with SSc and eight pregnancies occurred in six women with MCTD. The overall preterm delivery rate was 39% and small for gestational age infants occurred in 50% and 63% of pregnancies associated with SSc and MCTD, respectively. Fetal loss complicated two pregnancies in women with severe diffuse SSc and the antiphospholipid antibody syndrome. There were no cases of congenital heartblock among infants, and only one case of pre-eclampsia was observed. Maternal flares of disease during pregnancy were generally mild.

Most pregnancies in women with SSc and MCTD in this cohort were uncomplicated. The high rates of prematurity and small for gestational age infants underscore the risk for growth restriction consistent with the vasculopathy associated with these diseases.

Cloning, purification and characterization of a cellulase-free xylanase from Geobacillus thermodenitrificans AK53

Geobacillus thermodenitrificans AK53 xyl gene encoding xylanase was isolated, cloned and expressed in Escherichia coli. After purifying recombinant xylanase from G. thermodenitrificans AK53 (GthAK53Xyl) to homogeneity by ammonium sulfate precipitation and ion exchange chromatography, biochemical properties of the enzyme were determined. The kinetic studies for GthAK53Xyl showed K M value to be 4.34 mg/mL (for D-xylose) and V max value to be 2028.9 μmoles mg–1 min–1. The optimal temperature and pH for enzyme activity were found out to be 70°C and 5.0, respectively. The expressed protein showed the highest sequence similarity with the xylanases of G. thermodenitrificans JK1 (JN209933) and G. thermodenitrificans T-2 (EU599644). Metal cations Mg2+ and Mn2+ were found to be required for the enzyme activity, however, Co2+, Hg2+, Fe2+ and Cu2+ ions caused inhibitor effect on it. GthAK53Xyl had no cellulolytic activity and degraded xylan in an endo-fashion. The action of the enzyme on xylan from oat spelt produced xylobiose and xylopentose. The reported results are suggestive of a xylanase exhibiting desirable kinetics, stability parameters and metal resistance required for the efficient production of xylobiose at industrial scale.

Dietary supplementation with glutamine and γ-aminobutyric acid improves growth performance and serum parameters in 22- to 35-day-old broilers exposed to hot environment

This study was designed using 360 21-day-old chicks to determine the influences of diet supplementation with glutamine (5 g/kg), γ-aminobutyric acid (GABA, 100 mg/kg) or their combinations on performance and serum parameters exposed to cycling high temperatures. From 22 to 35 days, the experimental groups (2 × 2) were subjected to circular heat stress by exposing them to 30-34 °C cycling, while the positive control group was exposed to 23 °C constant. The blood of broilers was collected to detect serum parameters on days 28 and 35. Compared with the positive control group, the cycling high temperature decreased (p < 0.05) the feed consumption, weight gain and serum total protein (TP), glucose, thyroxine (T4), insulin, alkaline phosphatase (ALP), glutamine, GABA and glutamate levels, while increased (p < 0.05) the serum triglyceride (TG), corticosterone (CS), glucagon (GN), creatine kinase (CK), glutamic oxaloacetic transaminase (GOT), nitric oxide synthase (NOS), glutamate pyruvate transaminase (GPT) and lactate dehydrogenase (LDH) levels during 22-35 days. However, dietary glutamine (5 g/kg) increased (p < 0.05) the feed consumption, weight gain and serum levels of glutamine, TP, insulin and ALP, but decreased (p < 0.05) the serum TG, CK, GOT, NOS and GPT levels. Diet supplemented with GABA also increased (p < 0.05) weight gain and the serum levels of TP, T4, ALP, GABA and glutamine. In addition, the significant interactions (p < 0.05) between glutamine and GABA were found in the feed consumption, weight gain and the serum ALP, CK, LDH, GABA, T3 and T4 levels of heat-stressed chickens. This research indicated that dietary glutamine and GABA improved the antistress ability in performance and serum parameters of broilers under hot environment.

How to … place a lower bonded retainer

Post-orthodontic relapse of lower incisors is a common phenomenon. Sometimes a bonded retainer is fitted to prevent this relapse. In this article, we suggest a handy clinical technique of fitting a lower bonded retainer, which is convenient and easy to carry out.

Fluorides, orthodontics and demineralization: a systematic review

OBJECTIVES

To evaluate the effectiveness of fluoride in preventing white spot lesion (WSL) demineralization during orthodontic treatment and compare all modes of fluoride delivery.

DATA SOURCES

The search strategy for the review was carried out according to the standard Cochrane systematic review methodology. The following databases were searched for RCTs or CCTs: Cochrane Clinical Trials Register, Cochrane Oral Health Group Specialized Trials Register, MEDLINE and EMBASE. Inclusion and exclusion criteria were applied when considering studies to be included. Authors of trials were contacted for further data.

DATA SELECTION

The primary outcome of the review was the presence or absence of WSL by patient at the end of treatment. Secondary outcomes included any quantitative assessment of enamel mineral loss or lesion depth.

DATA EXTRACTION

Six reviewers independently, in duplicate, extracted data, including an assessment of the methodological quality of each trial.

DATA SYNTHESIS

Fifteen trials provided data for this review, although none fulfilled all the methodological quality assessment criteria. One study found that a daily NaF mouthrinse reduced the severity of demineralization surrounding an orthodontic appliance (lesion depth difference -70.0 microm; 95% CI -118.2 to -21.8 microm). One study found that use of a glass ionomer cement (GIC) for bracket bonding reduced the prevalence of WSL (Peto OR 0.35; 95% CI 0.15-0.84) compared with a composite resin. None of the studies fulfilled all of the methodological quality assessment criteria.

CONCLUSIONS

There is some evidence that the use of a daily NaF mouthrinse or a GIC for bonding brackets might reduce the occurrence and severity of WSL during orthodontic treatment. More high quality, clinical research is required into the different modes of delivering fluoride to the orthodontic patient.

Principal component and factor analysis to study variations in the aging lumbar spine

Human spine is a multifunctional structure of human body consisting of bones, joints, ligaments, and muscles which all undergo a process of change with the age. A sudden change in these features either naturally or through injury can lead to some serious medical conditions which puts huge burden on health services and economy. While aging is inevitable, the effect of aging on different areas of spine is of clinical significance. This paper reports the growth and degenerative pattern of human spine using principal component analysis. Some noticeable lumbar spine features such as vertebral heights, disc heights, disc signal intensities, paraspinal muscles, subcutaneous fats, psoas muscles, and cerebrospinal fluid were used to study the variations seen on lumbar spine with the natural aging. These features were extracted from lumbar spine magnetic resonance images of 61 subjects with age ranging from 2 to 93 years. Principal component analysis is used to transform complex and multivariate feature space to a smaller meaningful representation. PCA transformation provided 2-D visualization and knowledge of variations among spinal features. Further useful information about correlation among the spinal features is acquired through factor analysis. The knowledge of age related changes in spinal features are important in understanding different spine related problems.

Prevascular hernias of the abdominal wall: a difficult problem, a difficult repair

INTRODUCTION

Secondary prevascular hernias occurring anterior to the iliofemoral vessels and involving the lower abdominal wall are rare. These hernias can be difficult to repair because of loss of the inguinal ligament and the musculofascial elements of the inguinal region.

MATERIALS AND METHODS

We describe a new technique of repair using an intraperitoneal sling of prosthetic material. The sling is sewn posteriorly to the anterior surface of the sacrum, and is then draped caudally to be sewn to the pubis and Cooper's ligaments before being reflected anterior to be sewn to the posterior surface of the anterior abdominal wall. This sling "patches" the hernia defect as a form of intraperitoneal sublay.

CONCLUSIONS

We describe three such patients with satisfactory results at follow-ups of 8-16 months. Potential problems and considerations are discussed.

Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) depolymerase from Aspergillus sp. NA-25

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) degrading thermophilic fungus was isolated from soil sample collected from waste disposal site, Islamabad, Pakistan. It was able to grow efficiently on a medium containing PHBV as a sole source of carbon and has been identified as Aspergillus sp. NA-25 by 18S rRNA. Using 9% of inoculum maximum production of PHBV depolymerase was observed at 45 degrees C, pH 7.0 in the presence of 0.2% lactose as an additional carbon source. PHBV depolymerase was purified by precipitation with 80% ammonium sulfate and gel filtration chromatography on Sephadex G-75. The four enzyme forms obtained after gel filtration were analyzed on SDS-PAGE and their molecular weights (36, 68, 72 and 90 kDa) were determined. They were characterized on the basis of effect of different temperatures, pH, metal ions and different reagents on the PHBV activity and stability. It is obvious that the fungal strain Aspergillus sp. NA-25 is capable of degrading PHBV with the help of different types of depolymerases.

Degradation of polyisoprene rubber by newly isolated Bacillus sp. AF-666 from soil

Various microorganisms were screened for their ability to degrade polyisoprene rubber (natural rubber latex gloves). Strain AF-666, newly isolated from a soil sample, was selected as the best strain having the ability to grow on polyisoprene containing plates. The strain identified as Bacillus sp. AF-666, was found to degrade polyisoprene rubber, both on basal agar plates (latex overlay) as well as in liquid medium. Qualitative analysis of degradation was done through scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy SEM showed changes in surface morphology, like appearance of pits and cracks, and marked difference in transmittance spectra of test and control due to changes in the functional groups, was detected through FTIR. CO2 evolution as a result of rubber degradation, was calculated gravimetrically by Sturm Test. About 4.43 g/1 of CO2 was produced in case of test, whereas, 1.57 g/1 in case of control. The viable number of cells (CFU/ml) was also higher in test than in control. Present study may provide an opportunity for further studies on the applications of biotechnological processes as a tool for rubber waste management.

miRNA: small molecules as potential novel biomarkers in cancer

Four different types of small RNAs functionally associated with gene silencing have been discovered in animals including small interfering RNAs (siRNAs), microRNAs (miRNAs), and Piwi-interacting RNAs (piRNAs). Experimental evidence suggests that miRNAs regulate the expression of more than 30% of protein-coding genes. These molecules can also act as oncogenes or tumor suppressors. Expression profiling has revealed characteristic miRNA signatures not only in human cancers but also in serum and blood cells of cancer patients. Numerous human miRNA genes map to chromosomal regions which are susceptible to amplification, deletion or translocation in the process of tumor development. Despite the pivotal role of miRNA in cancer precise mechanisms of action are yet to be elucidated. This review is focused on recent findings related to the emerging field of miRNA serving as novel potential biomarkers in cancer diagnosis, prognosis and possibly, therapies.

Sclerosing mesenteritis presenting with complete small bowel obstruction, abdominal mass and hydronephrosis

Sclerosing mesenteritis is an uncommon and poorly understood inflammatory condition of the bowel mesentery which can often be confused with neoplasia, Crohn's disease and other inflammatory conditions. We describe a case of complete small bowel obstruction and right sided hydronephrosis due to sclerosing mesenteritis.

A review of 50 cases of aphakic detachment in Peshawar, North West Frontier Province of Pakistan

BACKGROUND

This prospective study was conducted at Khyber Teaching Hospital Peshawar, North West Frontier Province (NWFP) of Pakistan over the period of 16 months. It was to assess the demographic pattern, mode of presentation, treatment modalities and postoperative result of aphakic retinal detachment. This study also compared the incidence of aphakic retinal detachment in intracapsular versus extracapsular cataract extraction as well as the duration between cataract surgery and retinal detachment.

PATIENTS AND METHOD

A total of 50 patients were recruited in this prospective study. A Proforma was specially designed for this purpose. Detailed history with reference to age, sex, presenting complaints, spectacle wear, previous ocular surgery, duration of surgery/laser treatment, systemic and family history was taken. All patients had detailed ophthalmic examination, underwent conventional retinal reattachment surgery, and were followed up for 6 months.

RESULTS

Of the total number studied, 86% of the patients were males; only 14% were females, with a mean age of 58 years. The overall anatomical success was achieved in 40 (80%) eyes. The visual acuity of 6/12 and better was achieved in 8 (16%) eyes. 20 (40%) eyes attained a vision of 6/18 to 6/36. 12 (24%) eyes had a vision between 6/60 to CF 3m. The vision could not be improved beyond CF 3m in 10 (20%) eyes.

CONCLUSION

Vitreous loss during cataract surgery is the most common cause of aphakic retinal detachment. The risk is maximal in the first and second year. The overall anatomical attachment achieved through conventional retinal detachment surgery is 80%.

The intestinal trefoil factor (Tff3), also expressed in the inner ear, interacts with peptides contributing to apoptosis

The 3 members of the mammalian trefoil factor family (TFF) are expressed and secreted as cytoprotective peptides along the entire length of the normal gastrointestinal tract. More recently, they were shown to display multifunctional properties. Goblet cells of the small and large intestine constitute a major source for the synthesis of the third family member, TFF3 (formerly intestinal trefoil factor, ITF). TFF3, like the other family members, is rapidly up-regulated in response to physical wounding of the digestive tract. In addition, Tff3 was also detected in the posterior pituitary gland. Apart from this Tff3 function as a neuropeptide, also presence of Tff3 in the mouse cochlea was noted and Tff3-deficient animals display hearing impairment and accelerated presbyacusis. To elucidate Tff3's mode of function and its unexpected contribution to the hearing process, we strived to determine Tff3's interacting partners and to establish the functional network. To this end, we used a protein-protein binding assay based on a specific transcriptional regulation in yeast cells (the yeast-two-hybrid assay). We looked for interacting partners of Tff3 in a mouse cochlea cDNA library (from donors aged 3-15 days, P3-P15). Our data show that several binding candidates exist and that they could contribute to the known involvement of the trefoil peptides to apoptosis.

A novel poly(3-hydroxybutyrate)-degrading Streptoverticillium kashmirense AF1 isolated from soil and purification of PHB-depolymerase

A new bacterial strain, capable of degrading poly(3-hydroxybutyrate) (PHB) was isolated from soil. This organism, identified as Streptoverticillium kashmirense AF1, secreted PHB depolymerases both on solid as well as in liquid mineral salt medium containing poly(3-hydroxybutyrate) as sole carbon source. The optimum production of PHB depolymerase was observed at pH 8 and 7, at 45 degrees C, 1% substrate concentration and in the presence of lactose as an additional carbon source. The extracellular PHB depolymerase was purified by gel permeation chromatography using Sephadex G-75. The Streptoverticillium kashmirense AF1 produced two types of PHB depolymerases having molecular weights of about 37 and 45 kDa as determined by SDS-PAGE. The difference in dry cell mass and amount of CO2 evolved in the test and control calculated gravimetrically through Sturm test indicated the degradative capabilities of Streptoverticillium kashmirense AF1.

Extended-Spectrum β-Lactamases (ESBLs): Characterization, Epidemiology and Detection

Beta-lactamases of Enterobacteriaceae are the most important mechanism of resistance against beta-lactam drugs. Two types of beta-lactamases can confer resistance against 3rd generation cephalosporins. Chromosomally mediated beta-lactamases are inducible and are not inhibited by clavulanic acid. Resistance due to these enzymes is non-transferable. The 2nd type of enzyme is plasmid-mediated beta-lactamases, which are inhibited by clavulanic acid. These enzymes are more important clinically as these can be transferred between various species of Enterobacteriaceae. These enzymes are called extended-spectrum beta-lactamases (ESBLs). ESBL-producing Enterobacteriaceae have been responsible for numerous outbreaks of infection throughout the world and pose challenging infection control issues. Antibacterial choice is often complicated by multi-resistance. ESBLs can confer resistance against all beta-lactam drugs except carbapenems and cephamycins. Nursing home patients may be an important reservoir of ESBL-containing multiple antibiotic-resistant organisms. Use of broad-spectrum oral antibiotics and probably poor infection control practices may facilitate spread of this plasmid-mediated resistance. In addition to known populations at risk, ambulatory patients with chronic conditions represent another patient population that may harbor ESBL-producing organisms. Various methods can be used for detection of ESBLs in the laboratory. These tests include double disc diffusion test, Vitek ESBL test, E Tests, MIC Determination, genetic method, and isoelectric focusing (IEF).

Desmoplastic small round cell tumor masquerading as advanced ovarian cancer

Desmoplastic small round cell tumor (DSRCT) is a rare abdominal malignancy usually diagnosed in young adult males. Most patients have widespread disease at presentation, with an organ of origin difficult to ascertain. A 33-year-old female presented to her gynecologist with complaints of suprapubic pressure, abdominal pain, and increased abdominal girth. She had a large intraabdominal tumor on ultrasound, thought to be ovarian cancer. She underwent surgical exploration, which confirmed a malignancy, but the exact etiology was uncertain. Final pathology was consistent with DSRCT. DSRCT is a rare malignancy that can mimic other more commonly seen tumors such as lymphoma and ovarian cancer. When encountering an extensive intraabdominal malignancy of uncertain etiology, DSRCT should be in the differential diagnosis.

Gastric carcinoid: germline and somatic mutation of the neurofibromatosis type 1 gene

Neurofibromatosis type 1 (NF1) is one of the most common autosomal dominantly inherited conditions. A range of complications has been described, including gastrointestinal manifestations. Gastric carcinoid tumours are associated with multiple endocrine neoplasia, atrophic gastritis and pernicious anaemia but have not been reported in NF1 in the absence of other predisposing factors. We report the occurrence and investigation of a gastric carcinoid tumour in a 23-year-old woman with previously uncomplicated NF1. Analysis of the tumour tissue revealed loss of heterozygosity at the NF1 gene locus but a normal karyotype and an absence of microsatellite instability. A germline NF1 gene nonsense mutation in exon 37 was detected by denaturing high-performance liquid chromatography and DNA sequence analysis. This is the first reported occurrence of a gastric carcinoid tumour in a patient with NF1 in the absence of other predisposing factors such as pernicious anaemia. The analyses indicate that the carcinoid arose through NF1 gene inactivation but in the absence of an inherited NF1 gene microdeletion. This case adds to the range of gastrointestinal tumours that may be encountered in patients with NF1, particularly in those who present with upper gastrointestinal haemorrhage.

Purification and characterization of a mesophilic lipase from Bacillus subtilis FH5 stable at high temperature and pH

Lipases are a class of enzymes which catalyze the hydrolysis of long-chain triglycerides. Microbial lipases are currently receiving much attention with the rapid development of enzyme technology. Bacillus subtilis FH5, isolated from tannery wastes, produced a thermostable alkalophilic lipase and was purified to homogeneity as judged by SDS-PAGE. The purification steps included acetone fractionation and sequential column chromatography on DEAE-cellulose, Sephadex G-75 and adsorption chromatography on Hydroxylapatite. The results of chromatographies showed that two types of lipases were present having molecular weights approximately 62 kDa and 24 kDa, respectively. The purified enzyme was found to be 100% stable at pH 10 and about 80% residual activity was present at 60 degrees C. The enzyme was found to be stable in the presence of Mg2+, Mn2+ and Ca2+ ions. Km value was calculated as 5.05 mM and Vmax as 0.416 micromol/ml/min. Bacillus subtilis FH5 was isolated from tannery waste, therefore, enzyme is environmentally compatible for application in leather degreasing process.

Changes in esophageal motility after porfimer sodium photodynamic therapy for Barrett's dysplasia and mucosal carcinoma

Esophageal dysmotility is common in patients with Barrett's esophagus. Previously we have reported deterioration of esophageal motility after photodynamic therapy (PDT) in a heterogeneous group of patients with esophageal carcinoma. This prospective study in consecutive patients describes changes in motility noted after endoscopic ablation. Forty-seven patients referred to our institution for endoscopic ablation for Barrett's high grade dysplasia or mucosal carcinoma between August 2001 and May 2003 were prospectively evaluated with esophageal manometry before and after porfimer sodium PDT. Six patients did not complete the study. Manometry results were classified as normal, diffuse esophageal spasm, ineffective esophageal motility, or aperistalsis. Abnormal esophageal motility was found in 14 of 47 (30%) patients at study entry ([diffuse esophageal spasm] DES-3, [ineffective esophageal motility] IEM-7, Aperistalsis-4). After PDT, 11 of 41 patients with paired studies experienced a change in manometric diagnosis. Three patients had an improvement in motility, seven a worsening and one changed diagnosis, but did not particularly worsen or improve. No patient developed new aperistalsis. Therefore, abnormal motility was present in 19 of 41 (46%) patients after PDT (DES-2, IEM-14, Aperistalsis-3). There was a statistically significant (P = 0.016) relationship with longer segment Barrett's esophagus and deterioration of function. Baseline abnormalities in motility can occur in patients with Barrett's high-grade dysplasia or mucosal carcinoma. Changes in esophageal function also may occur following photodynamic therapy, but usually are not clinically significant. Worsening in function was more likely to occur in patients with longer segment Barrett's esophagus.

Appendix as a biliary conduit for choledochal cysts in children

Biliary conduits are constructed in operations for choledochal cysts. A wide variety of options are available for biliary tract reconstruction. We present our experience of treating six children with choledochal cysts by using the appendix as a biliary conduit. After mobilizing the appendix on its vascular pedicle, nonrefluxing, tunneled anastomosis was made with the 2nd part of the duodenum and the appendix. The operative procedure was simple and less time-consuming. Postoperative evaluation was done with the help of HIDA scan and ultrasound examination. Postoperative cholangitis was conspicuously absent in the two years of follow-up. One child has been lost to follow-up. From our preliminary experience, the operation seems simple and satisfying. Though the long-term efficacy still remains to be proven, the appendix should prove durable as a functional conduit.

Complete surgical excision of intramedullary schwannoma at the craniovertebral junction in neurofibromatosis type-2

Intramedullary spinal schwannomas are extremely rare. We describe a case of a 13-year-old female who was found to have an intramedullary schwannoma at craniovertebral junction along with incidental bilateral acoustic neuromas, which was excised completely. To our knowledge, this is the first report of a case of intramedullary schwannoma in association with NF-2 located at the craniovertebral junction. The literature has been reviewed with emphasis on radiological imaging, histopathological diagnosis and technique to achieve complete microsurgical excision.

Effect of amnioinfusion for meconium stained amniotic fluid on perinatal outcome

OBJECTIVE

To see the effect of amnioinfusion on perinatal outcome in cases of meconium staining of liquor.

METHODS

This study was conducted in department of Obstetrics and Gynaecology, unit 1, Jinnah Postgraduate Medical Centre, Karachi, from 1st January 1998 to 31st December 2000. Four hundred patients were included in this study, assigning 200 for amnioinfusion and 200 as control. All patients were matched in both the groups with respect to age, antenatal booking, parity, gestational age, stage of labour, colour of amniotic fluid and fetal birth weight. Both the groups were found to be comparable.

RESULTS

The rate of Caesarean section was found to be 37% in amnioinfusion group, which collaborates with other international studies. The fetal outcome was better i.e. 91% alive and healthy, after amnioinfusion due to dilution of meconium stained amniotic fluid with physiological solutions. The perinatal outcome was recorded by Apgar score at 5 minutes. The perinatal morbidity and mortality both were significantly lowered and was found to be 6% as compared to 14% in control, which was also noticed by less number of admissions in nursery i.e. 12% and perinatal deaths. The incidence of meconium aspiration syndrome was found to be 56% in control and was reduced to 22% after amnioinfusion in the other arm of the study.

CONCLUSION

These results are very encouraging and suggestion can be safely made that in future amnioinfusion will be the ideal method of preventing fetal distress due to meconium stained amniotic fluid.

Fluoridated elastomers: effect on disclosed plaque

OBJECTIVE

To investigate the effect of fluoridated elastomers on the quantity of disclosed dental plaque surrounding an orthodontic bracket in vivo.

DESIGN

A randomized, prospective, longitudinal clinical trial, employing a split mouth, crossover design.

SETTING

The Orthodontic Departments of Liverpool and Sheffield Dental Hospitals.

SUBJECTS AND METHODS

The subjects were 30 individuals about to start fixed orthodontic treatment. The study consisted of two experimental periods of 6 weeks with a washout period between. Fluoridated elastomers were randomly assigned at the first visit to be placed around brackets on 12, 11, 33 or 22, 21, 43. Non-fluoridated elastomers were placed on the contra-lateral teeth. After 6 weeks (visit 2) the elastomers were removed, the teeth disclosed and a photograph taken. Non-fluoridated elastomers were placed on all brackets for one visit to allow for a washout period. At visit 3, fluoridated elastomers were placed on the contra-lateral teeth to visit 1. At visit 4, the procedures at visit 2 were repeated. The photographs were scanned, then the area and proportion of the buccal surface covered with disclosed plaque was measured using computerized image analysis. A mixed-effects ANOVA was carried out with the dependent variable being the area or percentage area of disclosed plaque.

RESULTS

There was no evidence of a systematic error and substantial agreement for the repeat readings of the same images. The only significant independent variable for the area of disclosed plaque was the subject (p < 0.001). The significant independent variables for the proportion of disclosed plaque were the subject (p < 0.001) and the tooth type (p = 0.002). The independent variable describing the use of fluoridated or non-fluoridated elastomers was not significant for either the area or the proportion of disclosed plaque.

CONCLUSION

Fluoridated elastomers do not affect the quantity of disclosed plaque around an orthodontic bracket.

Effect of H. pylori infection on the expression of cyclooxygenase-2 in human gastric mucosa

Cyclooxygenase-1 is the primary isoform responsible for the production of cytoprotective prostaglandins (PGE(2) and PGI(2)) in the stomach. In contrast COX-2 is induced at the sites of inflammation. Using Helicobacter pylori infection as a model of inflammation, this study was designed to evaluate the effects of H. pylori infection on prostanoid synthesis and expression of COX-2 in human gastric mucosa. Prostaglandin (PGE(2)) and prostacyclin (PGI(2)) synthesis in gastric biopsies obtained from 21 patients undergoing diagnostic endoscopy, were determined. H. pylori was detected by CLO test, histology and culture. Biopsy samples were incubated either with NS-398, selective COX-2 inhibitor or aspirin. Samples were also treated with endotoxin (LPS) in order to induce COX-2 expression. Tissue was also analysed for COX-2 expression in vivo by immunohistochemistry. In 15 out of 21 patients, H. pylori was detected by at least two of the three methods. Higher levels of PGE(2) and PGI(2) were seen in patients infected with H. pylori (191+/-30 and 245+/-88ng/mg protein, respectively) compared with non-infected patients (77+/-17 and 120+/-36ng/mg protein, respectively). There was significant inhibition of PGE(2) and PGI(2) with aspirin in both H. pylori infected (28+/-6.6 and 53+/-43ng/mg, respectively) and in non-infected patients (16+/-7 and 12.5+/-3.5ng/mg protein, respectively). However, NS-398 and LPS did not alter prostaglandin function significantly. Immunohistochemistry in all patients irrespective of Hp status demonstrated expression of COX-2.Lower concentration of constitutive expression of COX-2 was detected in human gastric mucosa by immunohistochemistry, however, H. pylori infection failed to induce COX-2 protein. In addition, increased prostaglandin synthesis in Hp-infected patients appears to be COX-1 mediated rather than COX-2. Furthermore, failure of endotoxaemia-treated sample to produce more PGE(2) in the face of enhanced COX-2 expression in gastric mucosa further suggests that increased prostanoids in human gastric stomach are COX-1 mediated.