Prophylactic intra-arterial administration of fasudil hydrochloride for vasospasm following subarachnoid haemorrhage

PURPOSE

We evaluated patients treated with prophylactic intra-arterial administration of fasudil hydrochloride (IAF) after subarachnoid haemorrhage (SAH).

MATERIALS AND METHODS

Between August 1998 and December 2012, 92 patients with aneurysmal SAH were treated with IAF for angiographic vasospasm without ischemic symptoms after their follow-up angiography. Patients comprised 50 women and 42 men, aged 24-83 (mean 56.6) years. IAF consisted of 15 mg of fasudil hydrochloride dissolved in 20 ml physiological saline and injected through a catheter during approximately 15 min, after diagnostic angiography. The clinical outcome was evaluated using the Glasgow Outcome Scale (GOS) at discharge and ischemic lesions resulting from vasospasm were assessed on computed tomography (CT) scan at discharge.

RESULTS

Forty-eight patients underwent surgical clipping and 44 patients underwent endovascular coiling. Angiographic improvement was observed in all patients (100 %). At discharge, 76 (83.0 %) of 92 patients showed good recovery on GOS. Nine patients developed progression of delayed ischemic neurological deficits (DIND) and three of these patients had ischemic lesions on CT scans. No patient had any significant changes in vital signs or any other adverse effects resulting from IAF.

CONCLUSION

IAF therapy was safe and effective for patients with vasospasm following SAH. Prophylactic IAF therapy may prevent symptomatic vasospasm.

Crystallization and preliminary X-ray analysis of the NAD+-reducing [NiFe] hydrogenase from Hydrogenophilus thermoluteolus TH-1

NAD+-reducing [NiFe] hydrogenases catalyze the oxidoreduction of dihydrogen concomitant with the interconversion of NAD+ and NADH. Here, the isolation, purification and crystallization of the NAD+-reducing [NiFe] hydrogenase from Hydrogenophilus thermoluteolus TH-1 are reported. Crystals of the NAD+-reducing [NiFe] hydrogenase were obtained within one week from a solution containing polyethylene glycol using the sitting-drop vapour-diffusion method and micro-seeding. The crystal diffracted to 2.58 Å resolution and belonged to space group C2, with unit-cell parameters a=131.43, b=189.71, c=124.59 Å, β=109.42°. Assuming the presence of two NAD+-reducing [NiFe] hydrogenase molecules in the asymmetric unit, VM was calculated to be 2.2 Å3 Da(-1), which corresponds to a solvent content of 43%. Initial phases were determined by the single-wavelength anomalous dispersion method using the anomalous signal from the Fe atoms.

Fine-tuned regulation of the dissimilatory nitrite reductase gene by oxygen and nitric oxide in Pseudomonas aeruginosa

Nitrite reductase (NIR) catalyses the reduction of nitrite to nitric oxide (NO) in the denitrification pathway. In Pseudomonas aeruginosa, expression of the gene encoding NIR (nirS) is induced by NO and is under control of the NO-sensing regulator DNR (dissimilatory nitrate respiration regulator). Because DNR is under control of the oxygen-sensing regulator ANR (anaerobic regulator of arginine deiminase and nitrate reductase), nirS is expressed only under low oxygen and anaerobic conditions. Both ANR and DNR are FNR (fumarate and nitrate reductase regulator)-type regulators and recognize the consensus FNR-binding motif. The motif of the nirS promoter is thought to be recognized only by DNR, and not by ANR. Here, mutant strains expressing either ANR or DNR were constructed and used to analyse the role of ANR and DNR in the activation of nirS expression. Analysis of transcriptional activity by microarray and quantitative reverse transcription polymerase chain reaction revealed that nirS is transcribed under low oxygen conditions in an ANR-dependent manner, although the expression level was 10-fold lower than that of the DNR-dependent expression. An artificial promoter containing the FNR-binding motif of the nirS promoter was also twofold upregulated by ANR. These results indicate that low-level expression of NIR in the presence of nitrite may provide NO as a trigger for the full expression of denitrification genes when oxygen is depleted.

Involvement of a novel fermentative bacterium in acidification in a thermophilic anaerobic digester

Acidification results from the excessive accumulation of volatile fatty acids and the breakthrough of buffering capacity in anaerobic digesters. However, little is known about the identity of the acidogenic bacteria involved. Here, we identified an active fermentative bacterium during acidification in a thermophilic anaerobic digester by sequencing and phylogenetic analysis of isotopically labeled rRNA. The digestion sludge retrieved from the beginning of pH drop in the laboratory-scale anaerobic digester was incubated anaerobically at 55 °C for 4 h during which ¹³C-labeled glucose was supplemented repeatedly. ¹³CH₄ and ¹³CO₂ were produced after substrate addition. RNA extracts from the incubated sludge was density-separated by ultracentrifugation, and then bacterial communities in the density fractions were screened by terminal restriction fragment length polymorphism and clone library analyses based on 16S rRNA transcripts. Remarkably, a novel lineage within the genus Thermoanaerobacterium became abundant with increasing the buoyant density and predominated in the heaviest fraction of RNA. The results in this study indicate that a thermoacidophilic bacterium exclusively fermented the simple carbohydrate glucose, thereby playing key roles in acidification in the thermophilic anaerobic digester.

Adaptation of Hydrogenobacter thermophilus toward oxidative stress triggered by high expression of alkyl hydroperoxide reductase

Ferriperoxin is a novel peroxidase essential for aerobiosis of Hydrogenobacter thermophilus. Although the ferriperoxin-deficient mutant (Δfpx) was unable to grow aerobically, a suppressor mutant capable of aerobic growth was obtained after long aerobic cultivation. The alkyl hydroperoxide reductase gene was significantly upregulated in the suppressor mutant, indicating that the enzyme counteracts oxidative stress in the absence of ferriperoxin.

Reduction of Fe(III) oxides by phylogenetically and physiologically diverse thermophilic methanogens

Three thermophilic methanogens (Methanothermobacter thermautotrophicus, Methanosaeta thermophila, and Methanosarcina thermophila) were investigated for their ability to reduce poorly crystalline Fe(III) oxides (ferrihydrite) and the inhibitory effects of ferrihydrite on their methanogenesis. This study demonstrated that Fe(II) generation from ferrihydrite occurs in the cultures of the three thermophilic methanogens only when H2 was supplied as the source of reducing equivalents, even in the cultures of Mst. thermophila that do not grow on and produce CH4 from H2/CO2. While supplementation of ferrihydrite resulted in complete inhibition or suppression of methanogenesis by the thermophilic methanogens, ferrihydrite reduction by the methanogens at least partially alleviates the inhibitory effects. Microscopic and crystallographic analyses on the ferrihydrite-reducing Msr. thermophila cultures exhibited generation of magnetite on its cell surfaces through partial reduction of ferrihydrite. These findings suggest that at least certain thermophilic methanogens have the ability to extracellularly transfer electrons to insoluble Fe(III) compounds, affecting their methanogenic activities, which would in turn have significant impacts on materials and energy cycles in thermophilic anoxic environments.

Inhibitory effects of ferrihydrite on a thermophilic methanogenic community

The addition of ferrihydrite to methanogenic microbial communities obtained from a thermophilic anaerobic digester suppressed methanogenesis in a dose-dependent manner. The amount of reducing equivalents consumed by the reduction of iron was significantly smaller than that expected from the decrease in the production of CH4, which suggested that competition between iron-reducing microorganisms and methanogens was not the most significant cause for the suppression of methanogenesis. Microbial community analyses revealed that the presence of ferrihydrite markedly affected the bacterial composition, but not the archaeal composition. These results indicate that the presence of ferrihydrite directly and indirectly suppresses thermophilic methanogenesis.

Ochronotic spondylarthropathy: two case reports of progressive destructive changes in the hip

Abstract We report two cases of ochronotic spondylarthropathy who presented with spinal involvement followed by progressive destructive changes in the hip joint, which led to total hip replacement with a satisfactory outcome. Pathological examination revealed severe deterioration of the affected hip with unique cartilage degeneration associated with active inflammation in the synovium and bone marrow. These features were also evaluated by magnetic resonance imaging in one case which presented with rapidly destructive changes in the hip. Spinal involvement may contribute to progressive destructive hip arthropathy in ochronosis.

Enhancing the cellulose-degrading activity of cellulolytic bacteria CTL-6 (Clostridium thermocellum) by co-culture with non-cellulolytic bacteria W2-10 (Geobacillus sp.)

The effect of a non-cellulolytic bacterium W2-10 (Geobacillus sp.) on the cellulose-degrading activity of a cellulolytic bacterium CTL-6 (Clostridium thermocellum) was determined using cellulose materials (paper and straw) in peptone cellulose solution (PCS) medium under aerobic conditions. The results indicated that in the co-culture, addition of W2-10 resulted in a balanced medium pH, and may provide the required anaerobic environment for CTL-6. Overall, addition of W2-10 was beneficial to CTL-6 growth in the adverse environment of the PCS medium. In co-culture with W2-10, the CTL-6 cellulose degradation efficiency of filter paper and alkaline-treated wheat straw significantly increased up to 72.45 and 37.79 %, respectively. The CMCase activity and biomass of CTL-6 also increased from 0.23 U ml(-1) and 45.1 μg ml(-1) (DNA content) up to 0.47 U ml(-1) and 112.2 μg ml(-1), respectively. In addition, co-culture resulted in accumulation of acetate and propionate up to 4.26 and 2.76 mg ml(-1). This was a respective increase of 2.58 and 4.45 times, in comparison to the monoculture with CTL-6.