bluuebunny/crossref_metadata_2025 huggingface dataset:
High temperature stress tolerance in wheat genotypes: Role of antioxidant defence enzymes
Authors: Almeselmani M. , Deshmukh P. , Sairam R.
Published: June 2009

Two wheat genotypes, C 306 (tolerant) and PBW 343 (susceptible to temperature stress) were grown in growth chambers in the phytotron facility of IARI, New Delhi. The plants were maintained at 18/23°C (control) and 25/35°C (temperature stress) night/day temperatures after maximum tillering. Water potential was significantly reduced at anthesis, and at 7 and 15 days after anthesis in both genotypes in the heat stress treatment, and a greater reduction was recorded in PBW 343. The membrane stability index was also lower in the heat stress treatment in both genotypes at the vegetative stage, at anthesis and at 15 days after anthesis, and a greater reduction was observed in PBW 343 than in C 306. The hydrogen peroxide content increased as the plants advanced in age, and a higher hydrogen peroxide content was recorded in PBW 343 than in C 306 at different stages of growth in the heat stress treatment. The superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR) and peroxidase (POX) activities increased significantly at all stages of growth in C 306 in response to heat stress treatment, while PBW 343 showed a significant reduction in catalase, glutathione reductase and peroxidase activities in the high temperature treatment. Northern blot showed a significant increase in the
APX
-mRNA level under heat stress at the vegetative and anthesis stages, and the expression was greater in C 306. From the results it is apparent that the antioxidant defence mechanism plays an important role in the heat stress tolerance of wheat genotypes.
Enhancement of antioxidant enzyme activities and primary photochemical reactions in response to foliar application of thiols in water-stressed pearl millet
Authors: D’souza S. , Nathawat N. , Nair J. , Radha Krishna P. , Ramaswamy N. , Singh G. , Sahu M.
Published: June 2009

Primary photochemical reactions and the activities of the antioxidant enzymes chloroplastic superoxide dismutase (SOD), glutathione reductase (GR) and glutathione-S-transferase (GST) were determined in water-stressed pearl millet (
Pennisetum glaucum
L. cv. HHB-67) plants sprayed with the thiol compounds dithiothreitol (DTT), thioglycolic acid (TGA) and thiourea (TU) and the thiol modifiers 5,5′-dithio-bis-2-nitrobenzoic acid (DTNB) and N-ethylmaleimide (NEM) at the earhead emergence stage (47 days after sowing, DAS), together with a control. Sampling was done at 54 and 67 days after sowing. Photosystem I and II (PS I and II) activities (ferricyanide site) were found to increase in plants sprayed with TU, TGA and DTT at both stages (54 and 67 DAS), but a reduction in PS II activity (DCQ Site) compared with the control was caused by NEM (66.66%) and DTNB (27.77%) at 54 DAS. A similar decrease in the activity of PS II (ferricyanide site) was found at 67 DAS for DTNB (55.55%). The chloroplastic SOD activity increased in chloroplasts isolated from leaves sprayed with thiol compounds at both sampling stages, except for NEM at 54 and 67 DAS. The activities of GR and GST in the leaves were higher in thiol-treated plants than in the control at 54 and 67 DAS, while the lowest GR activity was seen for the sulphydryl modifiers (DTNB and NEM) in leaves at 54 DAS. The experimental data suggest an enhancement in the primary photochemistry and antioxidant enzyme activities of water-stressed pearl millet in response to foliar spraying with thiol compounds.
Effect of gamma radiation on antioxidant enzymes and G 6 PDH activities in Vicia faba plants
Authors: Moussa H.
Published: June 2009

The effect of gamma irradiation on
Vicia faba
L. plants was investigated by exposing dry seeds to doses ranging from 0 to 100 Gray (Gy) and studying the activities and isozyme patterns of the key enzymes involved in oxidative stress defence, such as superoxide dismutases (SOD, EC 1.15.1.1), catalases (CAT, EC 1.11.1.6), peroxidases (POX, EC 1.11.1.7), ascorbate peroxidases (APOX, EC 1.11.1.11), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4) and glutathione reductase (GR, EC 1.6.4.2), as well as the activity of an enzyme involved in a specific intermediary metabolic pathway, glucose-6-phosphate dehydrogenase (G
6
PDH, EC 1.1.1.49). The H
2
O
2
contents of faba bean leaves were also measured. None of the γ-irradiation doses used (0–100 Gy) had any effect on the activity of MDHAR, but they increased the enzyme activities of GR, APOX, SOD and G
6
PDH. Gamma rays at 20 Gy decreased the H
2
O
2
content, but the 100 Gy dose significantly increased the H
2
O
2
content compared with the non-irradiated plants. The results implied that the isozymes of SOD, CAT and POX present in faba bean cells growing in the presence of 0–15 Gy γ-irradiation are required to remove the reactive oxygen species (ROS) produced during normal, physiological processes. When the dose of γ-irradiation is ≥20 Gy, the level of ROS (produced indirectly by γ-irradiation) becomes too high to be dealt with by the existing antioxidant isozymes. The present research shows for the first time that the switch between the physiological oxidative response and a stress-related one occurs within a very narrow range of stress factor intensities, i.e. γ-irradiation doses. In the present study, this change took place between 15 and 20 Gy. Further investigations, using molecular biology techniques will be needed to determine the mechanisms involved in enzyme induction under ionizing conditions in order to evaluate changes in the gametic genomes at two possible levels: (i) the structural level, for studying mutations occurring in the DNA, and (ii) the functional level, by studying differential genetic expression between irradiated and non-irradiated plants.
Structure and Electrochemistry of Novel Silver Metal Oxyfluoride Perovskite: Cathode Materials for High Volumetric Energy Storage
Authors: Tong W. , Yoon W-S. , Amatucci G. G.
Published: June 2009

A novel electroactive nanostructured silver molybdenum oxyfluoride (SMOF) perovskite was successfully synthesized via mechanochemistry through the use of AgFx and MoO3. The structure of the SMOF perovskite has been examined utilizing X-ray powder diffraction (XRD) combined with X-ray absorption spectroscopy (XAS) and elemental analysis. The SMOF perovskite exhibited a very good electrochemical activity. A detailed in-situ electrochemical study by XRD and XAS was carried out. Finally, preliminary work on fabrication of a metallic Ag2F phase and optimization of the rate capability of SMOF perovskite is presented.
Computer Simulation of Structural Stability by Hydrogenation in Hydrogen Storage Materials
Authors: Katagiri Masahiko , Onodera Hidehiro , Ogawa Hiroshi
Published: June 2009

Microscopic mechanism of Hydrogen-Induced Amorphization (HIA) in AB2 C15 Laves phase compound is studied. Experimentally, compounds in which A atoms are contracted and B atoms are expanded in Laves phase show HIA. It suggests that the relative atomic size is the controlling factor. We investigate the role of the size effect by molecular Dynamics (MD) methods using Lennard-Jones pair-wise potentials. Our simulations show that in such a compound, the bulk modulus is remarkably reduced by hydrogenation compared to the isotropic tensile load, so that elastic instability is facilitated. This situation is caused by the negative increase of the pressure-fluctuation contribution in the elastic constant. The relaxation of B-atom positions by hydrogenation gives the fluctuation contribution. The fluctuation effect is essential in the elastic instability, although the energy change is small.
Multi-Well Deconvolution Algorithm for the Diagnostic, Analysis of Transient Pressure With Interference From Permanent Down-hole Gauges (PDG)
Authors: Zheng Shi-Yi , Wang Fei
Published: June 2009

Permanent Down-hole Gauge (PDG) has been widely installed in the oilfield around the world in recent years. One of the challenges in analyzing long-term, real-time, dynamic data such as transient pressure from PDG is the diagnostic and analysis of data with interference from other wells during the production. This type of data is very common in practice, while the published technique such as deconvolution algorithm failed in handling this problem.

Based on traditional interference test theory, muti-well deconvolution algorithm has been developed to address the problem in handling transient pressure with interference. A computer programme has been coded; a number of synthetic cases were studied, which proved that the developed algorithm works well for the problem stated above.

This paper presents the study results of applying the developed multi-well deconvolution technique in the diagnostic, processing and analysis of the numerically simulated transient pressure with interference. It was demonstrated that the interference effect can be identified, the published deconvolution algorithm failed in handling such data set, while the developed multi-well deconvolution algorithm worked well.

The paper shows that only after this data processing procedure, further analysis of the transient pressure data using methods such as decline curve analysis etc. is possible.
Fire Risk Reduction after Halon, by Using Emerging Technologies
Authors: Waterfall K. W. , Catchpole D. V. , Hamlin C. C.
Published: June 2009

The challenges posed by the Montreal Protocol and its subsequent amendments towards the reduction in usage of ozone depleting Halons have stimulated the fire protection industry to rethink its approach to fire protection management. This has promoted research and development of new techniques with low environmental risks and a more specific approach to reduction of fire risks.

In order to assist the Oil & Gas Industry in selecting the optimum means of protection for its activities the Exploration & Production (E&P) Forum of the industry has focused attention on risk reduction measures through its Fire Hazard Management Sub-Committee to produce guidance documentation and strategies. These cover the current position of regulatory trends and the technology applications. The contents of this paper disseminate the update guidance given by E&P Forum in its publications to phase out Halons and select alternative technologies, both for onshore and offshore facilities and developments.

The paper addresses the advantages and constraints of halon like gases, water mist systems, inert gas flooding, incipient fire detection and emerging technologies. This identifies the opportunities for effective fire protective design, incorporating current research into fire water applications and large tank fire protection and the consequent application of a low capital investment in fire protective systems and guidance to where inherent safety in design may be applied.
Stress Management and Accident Prevention
Authors: Benmebarek Samir
Published: June 2009

This study covers a Behavior-Based Approach to analyze accident causation factors, as stress related deviations from optimal human performance. Stress is addressed and singled out as being the "mother factor" behind the failure of human performance in the work environment.

A database of accident reports and statistics from an Offshore Oil Production Operating site, were taken as a live reference for the analysis. The scope and variety of activities involved, provided a valid cross section representing the workforce usually employed in this area.

Being usually performed in isolated, and sometimes severe environments, these activities offer an ideal reference to analyze stress related deviations.

A critical review and analysis of accident investigation reports, identified "stress" as being "the" root factor behind all accidents, other than catastrophic failure of equipment.

A novel definition of "stress" in terms of Personal Perceptual Factors, and their intimate combination with Environment Factors was drawn out and presented. The subsequent effects of this combination on the business objectives are highlighted, not only in terms of apparent accounted losses, when accidents do happen, but more importantly in terms of latent weaknesses in the System, that ultimately hamper the overall efficiency.

A methodology of approach for tackling and controlling the stress factor is proposed, and the necessity to include "Stress Management" as a major element of Health, Safety and Environment Policies, is recommended and substantiated as one of the best investments an Oil Company could make.
Organie Dye for Subsea Flowline Assessment
Authors: Khalil C. N. , Oliveira M. C. K.
Published: June 2009

Specific chemical additives are frequently used in the petroleum industry in order to obtain information regarding the flow conditions of water and oil in pipelines and reservoirs. The application of tracer agents supplies information, such as the free volume from a subsea pipeline under wax deposition. Among the available organic dyes, fluorescein is the most efficient tracer agent. Fluorescein exhibits intense fluorescence when in alkaline solution, under incidence of visible, or ultra-violet light and in concentrations of the order of 0.1 to 10 ppm.

In order to simplify the method for determining the free volume in subsea pipelines, a study was undergone for adapting an organic dye of strongly oleophilic nature. In this sense a derivative of fluorescein in the form of an ester of a higher alcohol was used, the main feature of which is its non-ionic character and its high solubility in a non-polar liquid, which renders possible its incorporation in the flow of the petroleum oil being produced, or in usual non-polar solvents such as kerosene, diesel oil or xylene.

The tracer agent originally soluble in the oil phase, when submitted to an alkaline treatment becomes fully soluble in water, and may be colorimetrically monitored The free volume of the pipelines may be accurately determined up to 98% by using this method.

Solubility experiments of the coloring were accomplished in several organic solvents, with subsequent alkaline extraction for several conditions. The conversion yields of the active principle of the dyes were determined by photometric methods.
Producing Oil Below the Water: Success Through Total Reservoir Management
Authors: Smith Grover E.
Published: June 2009

The Basal Oil Creek sandstone in this part of Garvin County, Oklahoma, is unconsolidated and produces heavy oil under a strong water drive. The geological and engineering studies conducted resulted in an unconventional, but correct, understanding of the manner of water influx into the oil reservoir. An additional two to five million barrels of recoverable oil were proven.
Minimizing Drilling Risk in Extended-Reach Wells at Valhall Using Geomechanics, Geoscience and 3D Visualization Technology
Authors: Kristiansen T. G. , Mandziuch K. , Heavey P. , Kol H.
Published: June 2009

In the Valhall field in the North Sea, significant resources have been identified in the flanks of the field. In this situation the reservoir targets are the main driver for the wellbore trajectory planning. Even if all of the traditional drilling parameters have been addressed and the well can be drilled on paper, the wellbore can experience wellbore stability problems (lost circulation, stuck pipe, tight hole). These wellbore problems can gradually progress or suddenly occur. The problems may be aggravated by mud properties or mechanical interaction between the rock and the drilling assembly.

Wellbore stability models, using offset drilling information, indicated early in the planning process at Valhall that the drilling of extended reach wells in the field was going to be a challenge. This challenge is the result of a narrow safe operational mud pressure window that narrows progressively with increasing wellbore sail angle. This theoretical window upper bound is given by lost circulation. The lower bound is given by the onset of wellbore collapse. This narrow window leaves hardly any room for the surge and swab pressures associated with pipe movement and pump changes.

The flank locations require sail angles close to 75 degrees in the overpressured unconsolidated claystone of Tertiary age. The record well to date had a build and hold trajectory at 74 degrees. On this record well around 3 MM USD was spent on fighting wellbore stability problems (around 750 hours). Since traditional wellbore stability analyses have already indicated a high risk of instability, and some wells have been successful, while others not, consideration was given to developing new tools to assist in the well planning in the overburden. We wanted to look at potential heterogeneous rock strength changes that could not be picked up using offset well information in the planning. The approach was to develop a more detailed geological model for the overburden with geologic formation top surfaces and 3D seismic coherency data. In this 3D data cube the drilling problems encountered on the offset wells were correlated along the wellbores. The 3D data presentation was done in a standard visualization software (GEOVIZ). The paper will present the geomechanical theory behind wellbore stability problems in faultzones and fractured rock mass, how the geologic model has been developed and how the visualization software is used to select a wellbore trajectory with the lowest risk of wellbore instability problems. Several case histories are included to illustrates the potential this methodology has for reducing unscheduled events due to wellbore instability problems while drilling the wellbore from the seafloor to the reservoir. Potential for further improvement is highlighted
Valuation of the Total Federal Economic Benefits Associated With the U.S. Dept, of Energy's NOSR 1 and 3 Properties in Western Colorado: A Case Study
Authors: Moritz E. C. , Lencioni L. C. , Grove K. W. , Hagemann S. G.
Published: June 2009

Recently, the U.S. government decided the Naval Petroleum and Oil Shale Reserves (NPOSR) were no longer strategically significant to the federal government. This prompted the U.S. Congress to order an evaluation of various options that included retention, transfer, or sale of the NPOSR by the Department of Energy (DOE).

The DOE retained Gustavson Associates, Inc. in 1996 to conduct a portion of the studies ordered by the U.S. Congress. For this paper, we profile the evaluation of NOSR 1 and 3, since it presented unique challenges. These include the evaluation of both surface and mineral rights, complex economic and regulatory issues specific to each option, the determination of applicable discount rates to government versus industry, and the effects of costs associated with environmental liabilities and compliance.

The following strategies were used to meet the challenges: 1) a multidisciplinary effort for evaluation of both the surface and mineral rights, 2) calculation of different discount rates that would apply to both government and industry, 3) use of a specialized model for projection of economic benefits to the federal government under each scenario, 4) research on comparable sales of similar surface and mineral properties, 5) adherence to appraisal standards for estimation of Fair Market Value, and 6) application of the unit rule when appraising both surface and mineral rights.
An Innovative Approach to Development of Adgas Hse Programme
Authors: Al-Zaabi Abdullah M. Obaid
Published: June 2009

In the 1970's and 1980's ADGAS managed Health, Safety and Environment (HSE) through development of various independent procedures like Permit to Work and Accident Reporting. In the early 1990's it had become obvious that there was a need to develop these and other procedures into a structured Safety Management System, this was achieved by adopting the International Safety Rating System (ISRS), ADGAS ultimately achieved a 3 Star Rating in ISRS.

ISRS was invaluable in helping ADGAS to enhance its Health and Safety performance through adoption of a wide ranging Safety Management System. However by the later half of the 1990's it was identified that the Safety performance has improved to a world class standard but had started to "plateau". The identified reason for the plateau were clear, lack of true ownership of ISRS in the line function as well as a poorly defined need to continually improve. This together with the need to incorporate Environment into the system led ADGAS to develop, in house a new HSE Management system called ADGAS HSEMS.

An innovative approach was taken by ADGAS in developing HSEMS which would satisfy the requirements of it's major shareholder, ADNOC, whilst being fully complaint with the Exploration & Production Forum recommendations for HSE Management Systems.

The System consists of 12 HSE Programmes which incorporate the Expectations of HSEMS. The expectations are met through development of Process Maps which simply and clearly define what is done to meet all, or part of the Expectation. Each Process

Map is described on one page and like a road map it helps people find their way around the system. The Process Map is a key clement in helping all employees understand what HSEMS means to them and to find out what the key performance measures are to measure the success of the Process.

To ensure that ADGAS achieved fill ownership of the system HSE Department facilitated the line function to develop the HSE Management System. The key to success being communication and involvement.

The structure of the HSEMS will be presented together with the development process and how continuous improvement is incorporated into the system. It will be shown how the HSE Management System will be clearly visible and understood by all employees, including how the HSE Policy and expectations will be met.
A Predictive Network Model for Three-Phase Flow in Porous Media
Authors: Lerdahl Thomas R. , Øren Pål-Eric , Bakke Stig
Published: June 2009

We reconstruct three-dimensional (3D) Berea sandstone samples by stochastically modeling the results of the main sandstone forming processes. The morphology of the reconstructed microstructure is compared quantitatively with a microtomography image of an actual sample of Berea sandstone. The comparison shows that the process based reconstruction adequately reproduces important intrinsic properties such as the local porosity distribution and the degree of connectivity. The reconstructed pore space is transformed into a pore network that is used directly as input to a network model. The model simulates two-phase flow and drainage dominated three-phase flow. Computed relative permeabilities for reconstructed Berea sandstone samples are compared with experimental data. The predicted relative permeability curves for both two-phase and three-phase flow compare favorably with the experimental results. Both the experiments and the simulations show that continuous oil layers present in the corners of gas invaded pores may allow low oil saturations to be reached during drainage dominated three-phase flow. However, the residual oil saturation and the oil permeability are strongly dependent on the saturation history.
Growth of Government Expenditure in Bangladesh: An Empirical Enquiry into the Validity of Wagner's Law
Authors: Kalam Mohammad Abul , Aziz Nusrate
Published: June 2009

The study empirically investigates ‘Wagner's law,' the relationship between ‘social progress' and ‘growth of state activity' in an economy, using Bangladesh data from 1976 to 2007 in a bivariate as well as a trivariate framework incorporating ‘population size' as a third variable. The estimated results provide evidence in favour of Wagner's law for Bangladesh in both the short-run and long-run. There is a long-run cointegration relation among real government expenditure, real GDP and the size of population where government expenditure is positively tied with the real GDP (1.14), per capita GDP (1.51) and population size (0.21). Both the real GDP and GDP per capita Granger cause total government expenditure to change. Population size also comes up as a significant stimulus for public spending to grow in both the long-run and short-run.
Tariffs, Horizontal Regulatory Standards and Protection against Foreign Competitors
Authors: Edwards Terence Huw
Published: June 2009

This paper focuses on a regulator's choice between setting a pure, horizontal technical barrier to trade (HTBT) or a tariff in a linear, Cournot duopoly, where a foreign firm competes with a local rival. Where a country is free to impose a tariff, it will not impose a HTBT. Only under a limited set of circumstances will the profit-shifting effect be sufficient to lead to total exclusion of the foreign firm: in other conditions, the country will set a tariff yielding some revenue. By contrast, if tariffs are constrained by international agreement, then the importing country will set an HTBT to exclude the foreign firm if and only if tariffs are reduced below a threshold level. Trade liberalisation agreements which only cover tariffs can reduce, rather than increase global welfare.
The Effect of Smoking in Young Adulthood on Smoking Later in Life: Evidence based on the Vietnam Era Draft Lottery
Authors: Eisenberg Daniel , Rowe Brian
Published: June 2009

An important, unresolved question for health policymakers and consumers is whether cigarette smoking in young adulthood has lasting effects into later adulthood. The Vietnam era draft lottery offers an opportunity to address this question, because it randomly assigned young men to be more likely to experience conditions favoring cigarette consumption, including highly subsidized prices. Using this natural experiment, we find that military service increased the probability of smoking by 35 percentage points as of 1978-80, when men in the relevant cohorts were aged 25-30, but later in adulthood this effect was substantially attenuated and did not lead to large negative health effects.
Use of Simulink's Non-Linear S-function to Simulate Feedback Temperature Control of a Heterogeneous Batch Reactor
Authors: Koçak Mehmet Çetin
Published: June 2009

This work has taken a heterogeneous batch reactor model from literature and converted it to Matlab and Simulink environments so that it can be used to develop new control techniques or test existing methods. Compartmentalised within a single S-function block of Simulink, it has been harnessed in this research to select a feedback controller for the task of raising the temperature of the reactor to a certain level as rapidly as possible, with minimum overshoot, and maintaining it there for the remainder of the reaction. The study has involved a thorough study of the original model and simulator, adaptation of the model to Matlab environments with suitable modification, development of a mini package in Matlab, open-loop verification by comparison with the original, construction of a Simulink diagram including the single S-function block housing both the reactor and the newly added temperature control loop, open-loop verification again, and finally interactive simulation runs to tune (optimize) the controller settings.
The Retinoblastoma Protein and Its Homolog p130 Regulate the G1/S Transition in Pancreatic β-Cells
Authors: Harb George , Vasavada Rupangi C. , Cobrinik David , Stewart Andrew F.
Published: June 2009

OBJECTIVE

The retinoblastoma protein family (pRb, p130, p107) plays a central role in the regulation of cell cycle progression. Surprisingly, loss of pRb in the β-cell has no discernible effect on cell cycle control. Therefore, we explored the effects of individual loss of either p130 or p107 in addition to the simultaneous loss of both pRb/p130 on the β-cell.

RESEARCH DESIGN AND METHODS

Adult mice deficient in either p130 or p107 or both pRb/p130 were examined for effects on β-cell replication, function, and survival. The Cre-Lox system was also used to inactivate pRb in wild-type and p130-deficient β-cells in vitro.

RESULTS

In vivo loss of either p107 or p130 did not affect β-cell replication or function. Combined pRb/p130 loss, however, resulted in dramatically accelerated proliferation as well as apoptotic cell death. Pancreas and β-cell mass were significantly reduced in double mutants. Despite this, overall glucose tolerance was normal, except for mild postprandial hyperglycemia. Ex vivo, acute deletion of pRb in p130-deficient β-cells also caused a striking increase in proliferation. The combined deletion of pRb/p130 upregulated islet expression of E2F2 but not E2F1.

CONCLUSIONS

These studies define an essential role for the pocket proteins in controlling the G1/S transition in β-cells. When deficient in both pRb and p130, β-cells undergo unrestrained cell cycle reentry and activation of apoptosis. These studies underscore the central role of the pRb pathway in controlling β-cell turnover and provide new cellular targets for β-cell regeneration.
Impact of Primary Care–Based Disease Management on the Health-Related Quality of Life in Patients With Type 2 Diabetes and Comorbidity
Authors: Ose Dominik , Wensing Michel , Szecsenyi Joachim , Joos Stefanie , Hermann Katja , Miksch Antje
Published: June 2009

OBJECTIVE

This study examined the effectiveness of the German diabetes disease management program (DMP) for patients with varying numbers of other medical conditions with respect to their health-related quality of life (HRQoL).

RESEARCH DESIGN AND METHODS

A questionnaire, including the HRQoL-measured EQ-5D, was mailed to a random sample of 3,546 patients with type 2 diabetes (59.3% female). The EQ-5D score was analyzed by grouping patients according to those on a DMP and those receiving routine care.

RESULTS

The analysis showed that participation in the DMP (P < 0.001), the number of other medical conditions (P < 0.001), and the interaction between the DMP and the number of other conditions (P < 0.05) had a significant impact on the EQ-5D score.

CONCLUSIONS

Our findings suggest that the number of other medical conditions may have a negative impact on the HRQoL of patients with type 2 diabetes. The results demonstrate that the German DMP for type 2 diabetes may help counterbalance this effect.
Glycemic Status and Brain Injury in Older Individuals
Authors: Saczynski Jane S. , Siggurdsson Sigurdur , Jonsson Palmi V. , Eiriksdottir Gudny , Olafsdottir Elin , Kjartansson Olafur , Harris Tamara B. , van Buchem Mark A. , Gudnason Vilmundur , Launer Lenore J.
Published: June 2009

OBJECTIVE

To examine the association of glycemic status to magnetic resonance imaging indicators of brain pathological changes.

RESEARCH DESIGN AND METHODS

This was a cross-sectional, population-based study of 4,415 men and women without dementia (mean age 76 years) participating in the Age Gene/Environment Susceptibility–Reykjavik Study. Glycemic status groups included the following: type 2 diabetes (self-report of diabetes, use of diabetes medications, or fasting blood glucose ≥7.0 mmol/l [11.1%]); impaired fasting glucose (IFG) (fasting blood glucose 5.6–6.9 mmol/l [36.2%]); and normoglycemic (52.7%). Outcomes were total brain volume, white and gray matter volume, white matter lesion (WML) volume, and presence of cerebral infarcts.

RESULTS

After adjustment for demographic and cardiovascular risk factors, participants with type 2 diabetes had significantly lower total brain volume (72.2 vs. 71.5%; P < 0.001) and lower gray and white matter volumes (45.1 vs. 44.9%, P < 0.01 and 25.7 vs. 25.3%, P < 0.001, respectively) and were more likely to have single (odds ratio 1.45 [95% CI 1.14–1.85]) or multiple (2.27 [1.60–3.23]) cerebral infarcts compared with normoglycemic participants. Longer duration of type 2 diabetes was associated with lower total brain volume and gray and white matter volume, higher WML volume (all Ptrend < 0.05), and a greater likelihood of single and multiple cerebral infarcts (all Ptrend < 0.01).

CONCLUSIONS

Type 2 diabetic participants have more pronounced brain atrophy and are more likely to have cerebral infarcts. Duration of type 2 diabetes is associated with brain changes, suggesting that type 2 diabetes has a cumulative effect on the brain.
Increased Left Ventricular Torsion in Uncomplicated Type 1 Diabetic Patients
Authors: Shivu Ganesh Nallur , Abozguia Khalid , Phan Thanh Trung , Ahmed Ibrar , Weaver Rebekah , Narendran Parth , Stevens Martin , Frenneaux Michael
Published: June 2009

OBJECTIVE

We used speckle tracking echocardiography to study the early changes in left ventricular (LV) torsion in young patients with uncomplicated type 1 diabetes and stress magnetic resonance imaging (MRI) to assess its interrelationships with coronary microangiopathy.

RESEARCH DESIGN AND METHODS

We recruited 33 asymptomatic subjects with type 1 diabetes and 32 age-matched healthy control subjects. All subjects underwent echocardiograms. Stress MRIs were performed in 30 subjects (8 healthy control subjects) to compute myocardial perfusion reserve index (MPRI).

RESULTS

A significant increase in LV torsion (2 ± 0.7 vs. 1.4 ± 0.7°/cm, P < 0.05) was identified in longer-term and retinopathy-positive type 1 diabetic subjects (1.9 ± 0.7 vs. 1.4 ± 0.7°/cm, P < 0.05) as compared with the healthy control subjects. The MPRI was independently associated with increased LV torsion.

CONCLUSIONS

We demonstrate that LV torsion is increased in young patients with uncomplicated type 1 diabetes and that coronary microvascular disease may play a key pathophysiological role in the development of increased LV torsion.
Primary endodermal sinus tumor presenting with spinal cord compression
Authors: Resnick Daniel K. , McLaughlin Mark R. , Albright A. Leland
Published: June 2009

✓ Endodermal sinus tumor is an uncommon malignant germ-cell neoplasm. These tumors usually present in childhood or young adulthood as testicular or ovarian masses; however, mediastinal and intracranial tumors have been described. The authors report the occurrence of a primary paraspinal endodermal sinus tumor in a 21-month-old boy who presented with thoracic spinal cord compression. A review of the literature failed to reveal a similar case. The clinical presentation, radiographic characteristics, operative findings, and patient outcome are discussed.
Hypoglossal—facial nerve side-to-end anastomosis for preservation of hypoglossal function: results of delayed treatment with a new technique
Authors: Sawamura Yutaka , Abe Hiroshi
Published: June 2009

✓ This report describes a new surgical technique to improve the results of conventional hypoglossal—facial nerve anastomosis that does not necessitate the use of nerve grafts or hemihypoglossal nerve splitting.

Using this technique, the mastoid process is partially resected to open the stylomastoid foramen and the descending portion of the facial nerve in the mastoid cavity is exposed by drilling to the level of the external genu and then sectioning its most proximal portion. The hypoglossal nerve beneath the internal jugular vein is exposed at the level of the axis and dissected as proximally as possible. One-half of the hypoglossal nerve is transected: use of less than one-half of the hypoglossal nerve is adequate for approximation to the distal stump of the atrophic facial nerve. The nerve endings, the proximally cut end of the hypoglossal nerve, and the distal stump of the facial nerve are approximated and anastomosed without tension. This technique was used in four patients with long-standing facial paralysis (greater than 24 months), and it provided satisfactory facial reanimation, with no evidence of hemitongue atrophy or dysfunction.

Because it completely preserves glossal function, the hemihypoglossal—facial nerve anastomosis described here constitutes a successful approach in patients with long-standing facial paralysis who do not wish to have tongue function compromised.
Radiosurgery for cerebral AVMs in children and adolescents: the neurobehavioral outcome
Authors: Riva Daria , Pantaleoni Chiara , Devoti Monica , Lindquist Christer , Steiner Ladislau , Giorgi Cesare
Published: June 2009

✓ Eight patients, ranging in age from 9 to 18 years, were treated for arteriovenous malformations using gamma knife radiosurgery and were evaluated an average of 6 years after treatment to record potential effects of radiosurgery on cognitive and neuropsychological performance. Tests for general intelligence, nonverbal intelligence, memory and its components, and attention performance were administered to patients and compared with test results of age-matched siblings or first cousins. No statistically significant difference was found between the performance of patients and controls in any of the tests administered. Additionally, a specially designed questionnaire completed by the patients, their parents, and their teachers revealed that the patients' emotional and relational behavior was stable and unchanged after treatment. No correlation was found between the neurocognitive test performance and the lesion volumes irradiated, but the lesion site was found to contribute to the type of deficit recorded after treatment. The less invasive nature of the radiosurgical approach, combined with the brevity or absence of hospitalization, presumably contributed to the patients' successful physical, mental, and emotional recovery.
Cerebral blood flow and temporal lobe epileptogenicity
Authors: Weinand Martin E. , Carter L. Philip , El-Saadany Waleed F. , Sioutos Panayiotis J. , Labiner David M. , Oommen Kalarickal J.
Published: June 2009

✓ Long-term surface cerebral blood flow (CBF) monitoring was performed to test the hypothesis that temporal lobe epileptogenicity is a function of epileptic cortical perfusion. Forty-three bitemporal 2-hour periictal CBF studies were performed in 13 patients. Homotopic regions of temporal cortex maintained interictal epileptic cortical hypoperfusion and nonepileptic normal cortical CBF. At 10 minutes preictus, a statistically significant, sustained increase in CBF was detected on the epileptic temporal lobe. Two minutes preictus, there was approximation of CBF in the epileptic and nonepileptic temporal lobes. Thereafter, electrocorticographic (ECoG) and clinical seizure onset occurred. The linear relationship between CBF in the two hemispheres (epileptic and nonepileptic) was the inverse of normal (y = −0.347x + 62.767, r = 0.470, df = 95, p < 0.05). The data indicated a direct linear correlation between epileptic cortical CBF and seizure interval (frequency−1), a clinical measure of epileptogenicity (r = 0.610, df = 49, p < 0.05). Epileptogenicity was also found to be a logarithmic function of the difference between nonepileptic and epileptic cortical perfusion (r = 0.564, df = 58, t = 5.20, p < 0.05). The results showed that progressive hypoperfusion of the epileptic focus correlated with a decreased seizure interval (increased epileptogenicity). Increased perfusion of the epileptic focus correlated with an increased seizure interval (decreased epileptogenicity). The fact that CBF alterations precede ECoG seizure activity suggests that vasomotor changes may produce electrical and clinical seizure onset.
Cerebral hyperglycolysis following severe traumatic brain injury in humans: a positron emission tomography study
Authors: Bergsneider Marvin , Hovda David A. , Shalmon Ehud , Kelly Daniel F. , Vespa Paul M. , Martin Neil A. , Phelps Michael E. , McArthur David L. , Caron Michael J. , Kraus Jess F. , Becker Donald P.
Published: June 2009

✓ Experimental traumatic brain injury studies have shown that cerebral hyperglycolysis is a pathophysiological response to injury-induced ionic and neurochemical cascades. This finding has important implications regarding cellular viability, vulnerability to secondary insults, and the functional capability of affected regions. Prior to this study, posttraumatic hyperglycolysis had not been detected in humans.

The characteristics and incidence of cerebral hyperglycolysis were determined in 28 severely head injured patients using [18F]fluorodeoxyglucose—positron emission tomography (FDG-PET). The local cerebral metabolic rate of glucose (CMRG) was calculated using a standard compartmental model. In six of the 28 patients, the global cerebral metabolic rate of oxygen (CMRO2) was determined by the simultaneous measurements of arteriovenous differences of oxygen and cerebral blood flow (xenon-133). Hyperglycolysis, defined as an increase in glucose utilization that measures two standard deviations above expected levels, was documented in all six patients in whom both FDG-PET and CMRO2 determinations were made within 8 days of injury. Five additional patients were found to have localized areas of hyperglycolysis adjacent to focal mass lesions. Within the 1st week following the injury, 56% of patients studied had presumptive evidence of hyperglycolysis.

The results of this study indicate that the metabolic state of the traumatically injured brain should be defined differentially in terms of glucose and oxygen metabolism. The use of FDG-PET demonstrates that hyperglycolysis occurs both regionally and globally following severe head injury in humans. The results of this clinical study directly complement those previously reported in experimental brain-injury studies, indicating the capability of imaging a fundamental component of cellular pathophysiology characteristic of head injury.
The suboccipital cavernous sinus
Authors: Arnautović Kenan I. , Al-Mefty Ossama , Pait T. Glenn , Krisht Ali F. , Husain Muhammad M.
Published: June 2009

✓ The authors studied the microsurgical anatomy of the suboccipital region, concentrating on the third segment (V3) of the vertebral artery (VA), which extends from the transverse foramen of the axis to the dural penetration of the VA, paying particular attention to its loops, branches, supporting fibrous rings, adjacent nerves, and surrounding venous structures.

Ten cadaver heads (20 sides) were fixed in formalin, their blood vessels were perfused with colored silicone rubber, and they were dissected under magnification. The authors subdivided the V3 into two parts, the horizontal (V3h) and the vertical (V3v), and studied the anatomical structures topographically, from the superficial to the deep tissues. In two additional specimens, serial histological sections were acquired through the V3 and its encircling elements to elucidate their cross-sectional anatomy. Measurements of surgically and clinically important features were obtained with the aid of an operating microscope.

This study reveals an astonishing anatomical resemblance between the suboccipital complex and the cavernous sinus, as follows: venous cushioning; anatomical properties of the V3 and those of the petrous—cavernous internal carotid artery (ICA), namely their loops, branches, supporting fibrous rings, and periarterial autonomic neural plexus; adjacent nerves; and skull base locations. Likewise, a review of the literature showed a related embryological development and functional and pathological features, as well as similar transitional patterns in the arterial walls of the V3 and the petrous-cavernous ICA. Hence, due to its similarity to the cavernous sinus, this suboccipital complex is here named the “suboccipital cavernous sinus.” Its role in physiological and pathological conditions as they pertain to various clinical and surgical implications is also discussed.
Multiple neoplasms following craniospinal irradiation for medulloblastoma in a patient with nevoid basal cell carcinoma syndrome
Authors: O'Malley Sean , Weitman David , Olding Michael , Sekhar Laligam
Published: June 2009

✓ A 28-year-old man presented to the authors' hospital with multiple intracranial tumors. At 2 years of age, he had undergone resection of a medulloblastoma and received adjunctive craniospinal irradiation. Subsequently, he was diagnosed with nevoid basal cell carcinoma syndrome, Gorlin's syndrome. Since his first presentation, he has required surgery for multiple basal cell carcinomas, an osteochondroma of the rib, two meningiomas, a trigeminal schwannoma, and a pleomorphic liposarcoma, all of which arose within the radiation field. Despite this impressive list of benign and malignant neoplasms, the patient is relatively well and leads a normal life. The authors examine the relationships between Gorlin's syndrome and radiation therapy and the subsequent development of tumors.
Vascular mechanisms in the pathophysiology of human spinal cord injury
Authors: Tator Charles H. , Koyanagi Izumi
Published: June 2009

✓ Vascular injury plays an important role in the primary and secondary injury mechanisms that cause damage to the acutely traumatized spinal cord. To understand the pathophysiology of human spinal cord injury, the authors investigated the vascular system in three uninjured human spinal cords using silicone rubber microangiography and analyzed the histological findings related to vascular injury in nine acutely traumatized human spinal cords obtained at autopsy. The interval from spinal cord injury to death ranged from 20 minutes to 9 months. The microangiograms of the uninjured human cervical cords demonstrated new information about the sulcal arterial system and the pial arteries. The centrifugal sulcal arterial system was found to supply all of the anterior gray matter, the anterior half of the posterior gray matter, approximately the inner half of the anterior and lateral white columns, and the anterior half of the posterior white columns. Traumatized spinal cord specimens in the acute stage (3–5 days postinjury) showed severe hemorrhages predominantly in the gray matter, but also in the white matter. The white matter surrounding the hemorrhagic gray matter showed a variety of lesions, including decreased staining, disrupted myelin, and axonal and periaxonal swelling. The white matter lesions extended far from the injury site, especially in the posterior columns. There was no evidence of complete occlusion of any of the larger arteries, including the anterior and posterior spinal arteries and the sulcal arteries. However, occluded intramedullary veins were identified in the degenerated posterior white columns. In the chronic stage (3–9 months postinjury), the injured segments showed major tissue loss with large cavitations, whereas both rostral and caudal remote sites showed well-demarcated necrotic areas indicative of infarction mainly in the posterior white columns. Obstruction of small intramedullary arteries and veins by the initial mechanical stress or secondary injury mechanisms most likely produced these extensive white matter lesions. Our studies implicate damage to the anterior sulcal arteries in causing the hemorrhagic necrosis and subsequent central myelomalacia at the injury site in acute spinal cord injury in humans.
Nearest-neighbor classification for identification of aggressive versus nonaggressive low-grade astrocytic tumors by means of image cytometry-generated variables
Authors: Decaestecker Christine , Salmon Isabelle , Dewitte Olivier , Camby Isabelle , Van Ham Philippe , Pasteels Jean-Lambert , Brotchi Jacques , Kiss Robert
Published: June 2009

✓ The authors investigated whether cytometry-related variables generated by means of computer-assisted microscopic analysis of Feulgen-stained nuclei can contribute significant information toward the characterization of low-grade astrocytic tumor aggressiveness. This investigation was conducted using the nearest-neighbor rule (a traditional classification method used in pattern recognition) to analyze a series of 250 supratentorial astrocytic tumors from adult patients. This series included 39 low-grade astrocytomas and 211 high-grade astrocytic tumors (including 47 anaplastic astrocytomas and 164 glioblastomas multiforme [GBMs]). The results show that the 3-nearest-neighbors rule enabled a subgroup of “atypical” astrocytomas to be distinguished from the “typical” tumors. The atypical astrocytoma species exhibited a DNA content (DNA ploidy level) and morphonuclear characteristics that were statistically more similar to the characteristics of GBMs than to those exhibited by the typical astrocytomas. An analysis of survival data revealed that patients with atypical astrocytomas survived for a significantly shorter period (p < 0.001) than patients with typical lesions of this kind. In fact, patients with atypical astrocytomas had a survival period similar to that of patients with anaplastic astrocytomas, whereas patients with typical astrocytomas had a survival period significantly longer (p < 0.0001) than those associated with anaplastic astrocytomas and GBMs.