Suppression of electron temperature gradient turbulence via negative magnetic shear in NSTX.

Negative magnetic shear is found to suppress electron turbulence and improve electron thermal transport for plasmas in the National Spherical Torus Experiment (NSTX). Sufficiently negative magnetic shear results in a transition out of a stiff profile regime. Density fluctuation measurements from high-k microwave scattering are verified to be the electron temperature gradient (ETG) mode by matching measured rest frequency and linear growth rate to gyrokinetic calculations. Fluctuation suppression under negligible E×B shear conditions confirm that negative magnetic shear alone is sufficient for ETG suppression. Measured electron temperature gradients can significantly exceed ETG critical gradients with ETG mode activity reduced to intermittent bursts, while electron thermal diffusivity improves to below 0.1 electron gyro-Bohms.

Electromagnetic transport from microtearing mode turbulence.

This Letter presents nonlinear gyrokinetic simulations of microtearing mode turbulence. The simulations include collisional and electromagnetic effects and use experimental parameters from a high-ß discharge in the National Spherical Torus Experiment. The predicted electron thermal transport is comparable to that given by experimental analysis, and it is dominated by the electromagnetic contribution of electrons free-streaming along the resulting stochastic magnetic field line trajectories. Experimental values of flow shear can significantly reduce the predicted transport.

Independent fermentation and metabolism of dietary polyphenols associated with a plant cell wall model.

Ingested polyphenols from plant-based foods are in part carried to the large intestine and metabolised by resident microbiota. This work investigated the release and microbial transformation of polyphenols adsorbed individually or in combination to apple cell walls (ACW) and pure (bacterial) cellulose (BC). BC and ACW, representing poorly- and highly-fermentable fibre models respectively, were used to investigate influences of interactions with polyphenols (cyanidin-3-glucoside, (±)-catechin, ferulic acid), on the release and microbial metabolism of polyphenols during in vitro digestion and fermentation. Bound polyphenols were partially released (20-70%) during simulated digestion, depending on polyphenol molecular structure. All remaining bound polyphenols were completely released and metabolised after 6-9 h by porcine large intestine microbiota, with formation of a number of intermediates and end-products. The same pathways of polyphenol microbial metabolism were observed in the presence and absence of ACW/BC, suggesting that microbial metabolism of polyphenols and carbohydrate substrates seems likely independent. Some polyphenol metabolism products were produced faster in the presence of carbohydrate fermentation, particularly of ACW. Microbial metabolism pathways of model polyphenols by a porcine faecal inoculum are not affected by being associated with BC or ACW, but the rate of metabolism is modestly enhanced with concurrent carbohydrate fermentation.

High-sensitive C-reactive protein is associated with reduced lung function in young adults.

Systemic inflammation has been associated with reduced lung function. However, data on the interrelationships between lung function and inflammation are sparse, and it is not clear if low-grade inflammation leads to reduced lung function. Associations between high-sensitive C-reactive protein (CRP) and spirometric lung function were assessed in a population-based cohort of approximately 1,000 Danes aged 20 yrs. In males, the average decline in forced expiratory volume in one second (FEV(1)) in the highest CRP quintile was 23 mL.yr(-1) versus 1.6 mL.yr(-1) in the lowest quintile. In females, the average decline was 6.2 mL.yr(-1) in the highest CRP quintile versus an increase of 1.8 mL.yr(-1) in the lowest CRP quintile. In a multiple regression analysis adjusted for sex, body mass index, cardiorespiratory fitness, smoking, asthma, airway hyperresponsiveness and serum eosinophil cationic protein, higher levels of CRP at age 20 yrs were associated with a greater reduction in both FEV(1) and forced vital capacity between ages 20 and 29 yrs. The findings show that higher levels of C-reactive protein in young adults are associated with subsequent decline in lung function, suggesting that low-grade systemic inflammation in young adulthood may lead to impaired lung function independently of the effects of smoking, obesity, cardiorespiratory fitness, asthma and eosinophilic inflammation.

Influence of different carbon sources on bacterial cellulose production by Gluconacetobacter xylinus strain ATCC 53524.

AIMS: To determine the effect of carbon sources on cellulose produced by Gluconacetobacter xylinus strain ATCC 53524, and to characterize the purity and structural features of the cellulose produced. METHODS AND RESULTS: Modified Hestrin Schramm medium containing the carbon sources mannitol, glucose, glycerol, fructose, sucrose or galactose were inoculated with Ga. xylinus strain ATCC 53524. Plate counts indicated that all carbon sources supported growth of the strain. Sucrose and glycerol gave the highest cellulose yields of 3.83 and 3.75 g l(-1) respectively after 96 h fermentation, primarily due to a surge in cellulose production in the last 12 h. Mannitol, fructose or glucose resulted in consistent rates of cellulose production and yields of >2.5 g l(-1). Solid state (13)C CP/MAS NMR revealed that irrespective of the carbon source, the cellulose produced by ATCC 53524 was pure and highly crystalline. Scanning electron micrographs illustrated the densely packed network of cellulose fibres within the pellicles and that the different carbon sources did not markedly alter the micro-architecture of the resulting cellulose pellicles. CONCLUSIONS: The production rate of bacterial cellulose by Ga. xylinus (ATCC 53524) was influenced by different carbon sources, but the product formed was indistinguishable in molecular and microscopic features. SIGNIFICANCE AND IMPACT OF THE STUDY: Our studies for the first time examined the influence of different carbon sources on the rate of cellulose production by Ga. xylinus ATCC 53524, and the molecular and microscopic features of the cellulose produced.

Mechanisms of action of intravesical bacillus Calmette-Guerin for bladder cancer.

Though superficial bladder-cancer patients have been treated with intravesical BCG since 1976, the mechanisms of action remain unknown. Evidence points towards an immune mechanism of BCG-induced antitumor activity. Although specific antitumor immunity may play a role in BCG immunotherapy, additional work is needed to more clearly define this possibility. Several investigators have noted a clinical association between favorable response to BCG therapy and a systemic response (DTH) to BCG antigen, indicated by conversion to a positive purified protein derivative (PPD) skin test. Additional animal studies have, in turn, documented evidence of specific binding between BCG and fibronectin found in the urothelial basement membrane, which appears necessary for the development of both the DTH response and antitumor activity. Other studies have suggested which cellular components of the immune system and lymphokines may be involved in the antitumor response. Further work will be needed to better understand BCG mechanisms, as these findings may be important to other forms of cancer therapy. Questions of immune suppression, genetic influence on the immune response, and immunocompetence at the time of surgery may assume increasing importance. A strong effort will therefore be needed to better understand these mechanisms so that patients may be selected, treated, and followed in a more effective manner.

Assessment of Micral-Test microalbuminuria test strip in the laboratory and in diabetic outpatients.

We have evaluated a semi-quantitative dry immunochemical screening method (Micral-Test) for the detection of low concentrations of albumin in urine. The stability of Micral-Test strips on storage was good, especially with regard to temperature, light and humidity. Changes in urine osmolality (urea and creatinine concentration), pH and sodium and potassium concentration did not have a significant analytical effect on the Micral-Test measurement; extremes of temperature altered the rate of colour development. The depth of dipping the strip into the sample and the timing of reading colour development were critical. We measured the albumin concentration in 184 urine samples from diabetic outpatients by the Micral-Test and by our in-house immunoturbidimetric method; a Micral-Test result of 20 mg/L had a sensitivity of 91% and specificity of 97% to predict a discriminating urine albumin concentration greater than 30 mg/L by the in house method. The Micral-Test is suitable for use by non-laboratory personnel and is capable of producing analytically acceptable results for use in diabetes clinics and by general practitioners.

[Atraumatic avascular necrosis of the femoral head in adults. Diagnosis and treatment]. / Atraumatisk avaskulaer nekrose i caput femoris hos voksne. Diagnostik og behandling.

Atraumatic avascular necrosis of the femoral head is a well-known disease which in the majority of cases is associated with conditions like alcohol abuse or steroid therapy. Early diagnosis is important, in particular in younger patients, in order to preserve the femoral head. Plain radiography, computed tomography, scintigraphy, and magnetic resonance imaging are the radiological methods used for detection of avascular necrosis, and especially magnetic resonance imaging has like scintigraphy been found to be well suited for diagnosis in early stages. Characteristic magnetic resonance scan patterns are described. Surgical treatment is necessary in most cases. Various methods are used, according to the stage of the disease.

Binding of polyphenols to plant cell wall analogues - Part 2: Phenolic acids.

Bacterial cellulose and cellulose-pectin composites were used as well-defined model plant cell wall (PCW) systems to study the interaction between phenolic acids (PA) derived from purple carrot juice concentrate (PCJC) and PCW components. Significant PA depletion from solution occurred, with pure cellulose initially (30s-1h) absorbing more than cellulose-pectin composites in the first hour (ca 20% cf 10-15%), but with all composites absorbing similar levels (ca 30%) after several days. Individual PAs bound to different relative extents with caffeic acid>chlorogenic acid>ferulic acid. Extrapolation of data for these model systems to carrot puree suggests that nutritionally-significant amounts of PAs could bind to cell walls, potentially restricting bioavailability in the small intestine and, as a consequence, delivering PAs to the large intestine for fermentation and metabolism by gut bacteria.

Dimits shift in realistic gyrokinetic plasma-turbulence simulations.

In simulations of turbulent plasma transport due to long wavelength (k perpendicular rhoi < or = 1) electrostatic drift-type instabilities, we find a persistent nonlinear up-shift of the effective threshold. Next-generation tokamaks will likely benefit from the higher effective threshold for turbulent transport, and transport models should incorporate suitable corrections to linear thresholds. The gyrokinetic simulations reported here are more realistic than previous reports of a Dimits shift because they include nonadiabatic electron dynamics, strong collisional damping of zonal flows, and finite electron and ion collisionality together with realistic shaped magnetic geometry. Reversing previously reported results based on idealized adiabatic electrons, we find that increasing collisionality reduces the heat flux because collisionality reduces the nonadiabatic electron microinstability drive.

Microtearing instabilities and electron transport in the NSTX spherical tokamak.

We report a successful quantitative account of the experimentally determined electron thermal conductivity chi(e) in a beam-heated H mode plasma by the magnetic fluctuations from microtearing instabilities. The calculated chi(e) based on existing nonlinear theory agrees with the result from transport analysis of the experimental data. Without using any adjustable parameter, the good agreement spans the entire region where there is a steep electron temperature gradient to drive the instability.

Lumbar disk herniation combined with epidural hematoma. A case report.

PURPOSE: Presentation of a case of simultaneous lumbar disk herniation and epidural hematoma. MATERIAL AND METHODS: An 85-year old patient with symptoms of compression of one or more nerve roots was examined with CT of the 3 lower lumbar intervertebral spaces. RESULTS: CT showed a high-density mass in the left side of the spinal canal, lying on the flaval ligament and extending laterally under the left pedicle of the 3rd lumbar vertebra. The correct diagnosis was not established before surgery. At surgery, a lumbar disk herniation and an epidural hematoma, located in the 3rd lumbar intervertebral space, were found. CONCLUSION: Retrospectively, the CT appearance was well in accordance with the findings at operation, but further examination, preferably MR imaging, is suggested in cases of atypical masses in the spinal canal.

Innovative surgical management of idiopathic retroperitoneal fibrosis.

Idiopathic retroperitoneal fibrosis is a rare entity usually treated with exploratory laparotomy, deep biopsies of the fibrotic process and uretrolysis. Innovative surgical management occasionally is required for ureteral obstruction. We report the use of dismembered pyeloplasty, autorenal transplantation and bilateral psoas hitch ureteral reimplantation for the management of ureteral obstruction associated with idiopathic retroperitoneal fibrosis.

Ureteronephroscopic marsupialization of obstructing peripelvic renal cyst.

Flexible ureteronephroscopy has been used for numerous therapeutic applications in the upper urinary tract. We report a case of a large peripelvic renal cyst causing obstruction to the ureteropelvic junction, which was treated by incising the wall of the cyst into the renal pelvis with the ureteronephroscope.

Sonographic and pathological staging of patients with clinically localized prostate cancer.

We evaluated 64 patients with clinically localized prostate cancer (on the basis of rectal examination, serum acid phosphatase, bone scan and pelvic computerized tomography scan) by transrectal sonography before radical prostatectomy. Of the 48 patients with histologically proved localized prostate cancer sonography overstaged the disease in 5 (10%) and correctly staged it in 43 (90%). All overstaged cancer patients were scanned after either prostatic biopsy (4) or transurethral prostatectomy (1) established the diagnosis of prostate cancer. Of the 16 patients with histologically proved, locally advanced prostate cancer (that is extracapsular extension and/or seminal vesicle invasion) sonography understaged the disease in 10 (62%) and correctly staged the disease in 6 (38%). These data suggest that sonography is associated with considerable staging errors when used to evaluate men with clinically localized prostate cancer.