Measurements of magnetic field fluctuations in TJ-II plasmas with new in-vessel helical arrays of magnetic coils

This paper describes two new helical arrays of magnetic coils recently installed inside the TJ-II vacuum vessel. Their main objective is the precise measurement of the spatial periodicity of the magnetohydrodynamic perturbations usually found in the TJ-II plasmas. Given the high probability of coil failures due to the harsh plasma environment and in view of the extremely difficult access to the TJ-II vessel interior for maintenance, the coil system has been divided in two quasi-identical helical arrays. Both arrays consist of 32 triaxial sensors measuring orthogonal components of the local magnetic field along an ideal helical path whose trajectory runs close to the plasma edge. A description of the main characteristics of coils and arrays as well as their nominal positioning along an ideal helical path, inside the vessel, is given. A precise experimental determination of the real spatial orientation of the coils is performed by comparing the signals measured in current ramp-up and ramp-down experiments with calculations based on a filamentary model for the TJ-II magnetic coils. After this fine calibration procedure, it is possible to analyze the dependence of the amplitude of the measured magnetic field and its fluctuations as a function of the coil distance to the last closed flux surface. The study of the phase evolution of the parallel and perpendicular oscillatory components is also enabled. Finally, two examples of mode number determination are shown. One corresponds to a low frequency mode appearing in pure electron cyclotron resonance heating plasma, and the other one shows several modes observed during combined injection of both co and counter neutral beams and identified as shear Alfvén waves.

Third-line rescue therapy with bismuth-containing quadruple regimen after failure of two treatments (with clarithromycin and levofloxacin) for H. pylori infection

BACKGROUND

Helicobacter pylori eradication therapy with a proton pump inhibitor (PPI), clarithromycin, and amoxicillin fails in >20 % of cases. A rescue therapy with PPI-amoxicillin-levofloxacin still fails in >20 % of patients.

AIM

To evaluate the efficacy and tolerability of a bismuth-containing quadruple regimen in patients with two consecutive eradication failures.

METHODS

Prospective multicenter study of patients in whom 1st treatment with PPI-clarithromycin-amoxicillin and 2nd with PPI-amoxicillin-levofloxacin had failed. A 3rd eradication regimen with a 7- to 14-day PPI (standard dose b.i.d.), bismuth subcitrate (120 mg q.i.d. or 240 mg b.i.d.), tetracycline (from 250 mg t.i.d. to 500 mg q.i.d.) and metronidazole (from 250 mg t.i.d. to 500 mg q.i.d.). Eradication was confirmed by (13)C-urea-breath-test 4-8 weeks after therapy. Compliance was determined through questioning and recovery of empty medication envelopes. Adverse effects were evaluated by means of a questionnaire.

RESULTS

Two hundred patients (mean age 50 years, 55 % females, 20 % peptic ulcer/80 % uninvestigated-functional dyspepsia) were initially included, and two were lost to follow-up. In all, 97 % of patients complied with the protocol. Per-protocol and intention-to-treat eradication rates were 67 % (95 % CI 60-74 %) and 65 % (58-72 %). Adverse effects were reported in 22 % of patients, the most common being nausea (12 %), abdominal pain (11 %), metallic taste (8.5 %), and diarrhea (8 %), none of them severe.

CONCLUSION

A bismuth-containing quadruple regimen is an acceptable third-line strategy and a safe alternative after two previous H. pylori eradication failures with standard clarithromycin- and levofloxacin-containing triple therapies.

Improved sea-urchin embryo bioassay for in situ evaluation of dredged material

Sediments usually contain many contaminants derived from human activities. In case of dredging activities, these sediment-bound contaminants arise following the excavation and remobilization of sediments. Previous studies have used different species of clam, crabs, lugworms, etc. for the evaluation of dredged material in situ, but there are not studies that use acute bioassays for these purposes. The sea-urchin embryo bioassay has been chosen to characterize biological effects in situ in two ports of the southwest of Spain, the Port of Huelva and the Port of Cadiz. The sea-urchin embryo bioassay has been adapted for in situ evaluation of seawater quality in coastal areas, however, they are necessary for further improvements to take into account differences of temperature between sites. This temperature variation is one of the principal reasons (other than pollution) of larval mortality and the slow down in the growth rate of the urchin. In the present study a bioassay was conducted in both field and laboratory conditions, in order to compare the effects in situ with the effects under controlled conditions of temperature, salinity and oxygen dissolved. Results showed a good correlation between samples obtained in situ and in the laboratory, but in the field the percentage of normal pluteus larvae is less than under laboratory conditions.

Microsomal prostaglandin E synthase-1, which is not coupled to a particular cyclooxygenase isoenzyme, is essential for prostaglandin E(2) biosynthesis in vascular smooth muscle cells

BACKGROUND

Prostaglandin (PG) E(2) induces expression of matrix metalloproteinases and angiogenic factors, thereby contributing to plaque instability.

OBJECTIVE

To study the influence of cyclooxygenase (COX) and PGE synthase (PGES) isoenzyme expression on PGE(2) and PGI(2) biosynthesis in vascular smooth muscle cells (VSMC) in culture.

METHODS

Cells were treated with human recombinant IL-1beta over different periods of time. Expression of PGI synthase, and COX and PGES isoenzymes was determined by real-time reverse transcriptase polymerase chain reaction and immunoblotting. Biosynthesis of prostanoids from exogenous or endogenous substrate was analyzed by high-performance liquid chromatography or enzyme-immunoassay after incubation of cells with labeled arachidonic acid or thrombin, respectively.

RESULTS

Cytosolic PGES and microsomal PGES (mPGES) -1 and -2 were expressed in VSMC. PGES activity was mainly linked to mPGES-1. IL-1beta induced COX-2 and mPGES-1 with a different time course. VSMC ability to synthesize PGE(2) and PGI(2) fitted mPGES-1 and COX-2 expression, respectively. The ability of VSMC to produce PGI(2) was downregulated by mPGES-1 expression and was restored when mPGES-1 expression was silenced. Results from COX-1 and COX-2 silencing and selective inhibition showed that both COX-1 and COX-2 were involved in the biosynthesis of PGE(2) and their relative contribution depended on the time of incubation with IL-1beta.

CONCLUSIONS

mPGES-1 is the main PGES responsible for PGE(2) biosynthesis by VSMC and its induction downregulates VSMC ability to produce PGI(2.) These results support the concept that under inflammatory conditions VSMC could significantly contribute to plaque instability and that mPGES-1 may be a target for therapeutic intervention in patients with cardiovascular risk.

Cross-reactivity among amide-type local anesthetics in a case of allergy to mepivacaine

Among the various adverse reactions to local anesthetics, IgE-mediated reactions, particularly to the more commonly used amide group, are extremely rare. We report the case of a 39-year-old man who suffered itching and generalized urticaria with facial angioedema 15 minutes after administration of mepivacaine. Skin tests revealed a strong positive reaction to mepivacaine, lidocaine, and ropivacaine, but negative reactions to bupivacaine and levobupivacaine. Furthermore, double-blind placebo-controlled subcutaneous challenge with bupivacaine and levobupivacaine was well tolerated. We conclude that an extensive allergologic study must be carried out in rare cases of true allergic reaction to amide-type local anesthetics in order to rule out cross reactivity.

Stereoselective biosynthesis of hepoxilin B3 in human epidermis

We previously reported that normal human epidermis forms 12-oxo-eicosatetraenoic acid and hepoxilin B3 as major eicosanoids and that hepoxilins and trioxilins are dramatically elevated in psoriatic lesions. We also observed that normal epidermis only synthesized one of the two possible 10-hydroxy- epimers of hepoxilin B3, suggesting its enzymatic origin. This study investigated the enzymatic pathways involved in the formation of hepoxilin B3 in human epidermis. Human epidermal fragments or cell fractions were incubated with [14C]-arachidonic acid or authentic 12(S)-hydroperoxyeicosatetraenoic acid. Products were analyzed by high-performance liquid chromatography, gas chromatography-mass spectrometry or a combination of both techniques. Esculetin and nordihydroguaiaretic acid inhibited formation of hepoxilin B3, 12-oxo-eicosatetraenoic acid, trioxilins, and 12-hydroxyeicosatetraenoic acid in a concentration-dependent manner. 12-Lipoxygenase activity was mainly located in the microsomal fraction (100,000 x g pellet) and 12-hydroxyeicosatetraenoic acid, hepoxilin B3, and 12-oxo-eicosatetraenoic acid were formed. The hepoxilin B3-synthesizing activity was not observed in subcellular fractions incubated with authentic 12(S)-hydroperoxyeicosatetraenoic acid, although it was located at least in the microsomal fraction when incubated with arachidonic acid. Similar results were obtained using preparations of recombinant platelet-type 12-lipoxygenase that yielded 12-oxo-eicosatetraenoic acid and hepoxilin B3 in addition to 12-hydroxyeicosatetraenoic acid, when incubated with arachidonic acid but not when incubated with 12-hydroperoxyeicosatetraenoic acid. Nevertheless, recombinant 12-lipoxygenase produced a lower ratio of 12-oxo-eicosatetraenoic acid and hepoxilin B3-12-hydroxyeicosatetraenoic acid than epidermis. Our results support the concept that 12-lipoxygenase catalyzes the formation of hepoxilin B3 and 12-oxo-eicosatetraenoic acid.

Occurrence of hepoxilins and trioxilins in psoriatic lesions

We recently found that normal human epidermis produces relatively high amounts of hepoxilins and trioxilins in vitro. Therefore, the aim of this study was to demonstrate the presence of these compounds in psoriatic lesions. Extracts from scales of patients with chronic stable plaque psoriasis were analyzed by a combination of high performance liquid chromatography and gas chromatography-mass spectrometry techniques. We found that the levels of hepoxilin B3 were more than 16-fold higher in psoriatic scales than in normal epidermis (3.2+/-2.3 and < 0.2 ng per mg, respectively), whereas hepoxilin A3 was not detected in any sample. Trioxilins were semiquantitated and referred to 12-hydroxyeicosatetraenoic acid, ratios of trioxilins A3 and B3 12-hydroxyeicosatetraenoic acid in psoriatic lesions were 0.65+/-0.23 and 0.32+/-0.28, respectively, and they were not detected in normal epidermis. The presence of a great amount of trioxilin A3 strongly suggests that hepoxilin A3 was present in psoriatic lesions and it was totally degraded to trioxilin A3 during the analysis procedure. Our results demonstrate that hepoxilins and trioxilins are produced by human skin in vivo and that the levels of these compounds are increased in psoriasis. The reported biologic activities of hepoxilins indicate that they could amplify and maintain the inflammatory response. Our results reinforce the idea that these compounds could play a role as mediators in the inflammatory response in skin, particularly in psoriasis.

Interleukin-1 enhances the ability of cultured human umbilical vein endothelial cells to oxidize linoleic acid

Human umbilical vein endothelial cells (HUVEC) were treated with recombinant interleukin (IL)-1 beta, and the metabolism of exogenous linoleic acid was studied. High performance liquid chromatography, gas chromatography-mass spectrometry, and chiral analysis revealed that HUVEC enzymatically convert linoleic acid mainly into 13-(S)hydroxy-9(Z),11(E)-octadecadienoic (13-HODE) and 9-(R)hydroxy-10(E),12(Z)-octadecadienoic acids, which may isomerize toward all-trans compounds. IL-1 beta increased the formation of all octadecanoids in a time- and dose-dependent manner with similar EC50 (approximately 1 unit/ml). The apparent Km values of linoleic acid were 15.59 +/- 8.39 and 152.9 +/- 84 microM (p < 0.05) in IL-1 beta-treated cells and controls, respectively, indicating a higher substrate affinity in cells stimulated with IL-1 beta. Ratios of S/R enantiomers for the hydroxyoctadecanoids produced by untreated and IL-1 beta-treated cells were similar to those from isolated cyclooxygenases (COXs), whereas isolated 15-lipoxygenase yielded 13-HODE with a strict S configuration. The formation of octadecanoids was inhibited in a dose-dependent manner by several COX inhibitors in both controls and IL-1 beta-treated cells, COX2 selective inhibitors being more effective on IL-1 beta-treated cells than on controls. COX1 and COX2 protein levels increased less than 2-fold and 8-fold, respectively, after IL-1 beta treatment. The specificity of COX inhibitors was proven since they did not inhibit 13-HODE formation by human polymorphonuclear leukocytes. Overall, these results indicate that COXs are responsible for the oxidative metabolism of linoleic acid in HUVEC, and IL-1 beta increases it by inducing the expression of new enzyme, mainly COX2.

Characterization of arachidonic acid metabolites through the 12-lipoxygenase pathway in human epidermis by high-performance liquid chromatography and gas chromatography/mass spectrometry

Fragments of human epidermis were incubated in the presence of exogenous arachidonic acid. The incubates were subjected to reversed-phase and straight-phase high-performance liquid chromatography and finally the identity of the arachidonic acid metabolites of the 12-lipoxygenase pathway was determined by means of gas chromatography/mass spectrometry. It was found that human epidermis produces 8-hydroxy-11,12-epoxy- and 10-hydroxy-11,12-epoxyeicosatrienoic acid, 8,9,12-, 8,11,12- and 10,11,12-trihydroxyeicosatrienoic acid, 12-keto-eicosatetraenoic acid and 12-hydroxy-eicosatetraenoic acid derived from arachidonic acid via the 12-lipoxygenase pathway. As far as is known, this is the first time that a systematic and complete characterization of arachidonic acid metabolism through the 12-lipoxygenase pathway in human epidermis has been reported. Some of the eicosanoids characterized have potent biological activities that suggest their role in the inflammatory response on human skin.

[Type I pseudohypoparathyroidism. Study and prolonged follow-up of a case]

The prolonged evolution of a case of pseudohypoparathyroidism with hereditary osteodystrophy (AHO) and osteitis fibrosa is presented. The diagnosis was confirmed by the existence of a peculiar phenotype, hypocalcaemia, hyperphosphatemia, increased PTH values, and a lack of tubular response after PTH and radiological signs of hyperparathyroidism. The clinical and biochemical evolution, under 1.25 (OH)2D3 therapy with special emphasis on the growth and development were shown. The bibliography was also reviewed.