[Development of versatile oxidation systems based on the design of oxoammonium salts]

Organic nitroxyl radical catalysts have recently attracted great attention because they realize efficient alcohol oxidation under mild and environmentally benign conditions. A representative of this class is 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO). We have also developed 2-azaadamantane N-oxyls (AZADOs) as highly efficient oxidation catalysts. These nitroxyl radicals are generally oxidized by a cooxidant to generate oxoammonium salts, which are active species for alcohol oxidation. In the oxidation systems presented in this paper, we focus on the differences between these two species in terms of oxidation state and counter anion. Herein, the effects of a counter anion of an oxoammonium species on its reaction selectivity are shown. On the basis of the control of the counter anion, we have developed catalytic oxidative rearrangement of tertiary allylic alcohols to β-substituted α,β-unsaturated carbonyl compounds. Moreover, we have developed novel useful oxidation systems utilizing a catalytic oxoammonium salt; namely, a one-pot oxidation of primary alcohols to carboxylic acids and an aerobic alcohol oxidation.

Effects of intrathecal administration of nicardipine and nifedipine on chronic cerebral vasospasm in dogs

Chronic cerebral vasospasm after subarachnoid haemorrhage (SAH) responds poorly to systemic administration of dihydropyridine calcium antagonists. However, the spastic arteries can be dilated by the topical (intrathecal) administration of the drugs. We examined by angiography the spasmolytic effects of intrathecal (cisternal) administration of nicardipine (0.1 mg 1 ml ) or nifedipine (0.1 mg 1 ml ) on day 7 of SAH made by the two-haemorrhage model in dogs. Both drugs dilated the spastic basilar artery from 15 min till 4 hours after the drug administration. The increase in the diameter of the basilar artery between 1 and 3 hours was statistically significant in both groups. Intrathecal administration of nicardipine which is water soluble, may be useful in the treatment of chronic cerebral vasospasm in patients.

Organocatalytic one-pot oxidative cleavage of terminal diols to dehomologated carboxylic acids

The organocatalytic one-pot oxidative cleavage of terminal 1,2-diols to one-carbon-unit-shorter carboxylic acids is described. The combination of 1-Me-AZADO (cat.), NaOCl (cat.), and NaClO(2) caused smooth one-pot oxidative cleavage under mild conditions. A broad range of substrates including carbohydrates and N-protected amino diols were converted without epimerization. Terminal triols and tetraols respectively underwent cleavage of their C-2 and C-3 moieties to afford their corresponding two- and three-carbon-unit-shorter carboxylic acids.

Successful treatment of duodenal carcinoid tumor by laparoscopy-assisted endoscopic full-thickness resection with lymphadenectomy

Reports on endoscopic full-thickness resection of the duodenum using the endoscopic submucosal dissection technique are rare. Here we present a case of a duodenal bulb carcinoid tumor successfully treated by laparoscopy-assisted endoscopic full-thickness resection (LAEFR). An asymptomatic 65-year-old woman had a 10-mm, submucosal tumor on the anterior wall of the duodenal bulb. Abdominal CT revealed an enlarged lymph node adjacent to the duodenum and pancreas. Although we informed the patient of the need for pancreatoduodenectomy with a lymphadenectomy, the patient expressly requested LAEFR. After negative nodal metastasis was confirmed by an intraoperative frozen section of the enlarged nodes, LAEFR was performed using the endoscopic submucosal dissection technique under the laparoscopic assistance. The duodenal wall defect was closed by laparoscopy with an Albert anastomosis. The entire circumferential margin of the specimen was histopathologically negative for carcinoid tumor cells. In summary, LAEFR enables en bloc and whole-layer excision of nonperiampullary duodenal lesions with a sufficient surgical margin, both vertically and laterally. LAEFR is a minimally invasive and effective treatment for selected patients with duodenal carcinoid tumor.

9-Azanoradamantane N-oxyl (Nor-AZADO): a highly active organocatalyst for alcohol oxidation

A highly active organocatalyst for alcohol oxidation has been developed. 9-Azanoradamantane N-oxyl (Nor-AZADO 4), constituting an unhindered, stable nitroxyl radical, exhibits superior catalytic activity to 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and AZADOs in the oxidation of alcohols to their corresponding carbonyl compounds.

Oxidation of alcohols to carbonyl compounds with diisopropyl azodicarboxylate catalyzed by nitroxyl radicals

A nitroxyl-radical-catalyzed oxidation of alcohols using diisopropyl azodicarboxylate (DIAD) as the terminal oxidant is reported. A variety of primary and secondary alcohols including aliphatic, benzylic, and allylic alcohols are efficiently oxidized to their corresponding aldehydes and ketones without overoxidation to carboxylic acid. 1,2-Diols are oxidized to hydroxyl ketones or diketones depending on the amount of DIAD used.

Electron density measurement of cesium seeded negative ion source by surface wave probe

Electron density measurements of a large-scaled negative ion source were carried out with a surface wave probe. By comparison of the electron densities determined with the surface wave probe and a Langmuir probe, it was confirmed that the surface wave probe is highly available for diagnostic of the electron density in H(-) ion sources. In addition, it was found that the ratio of the electron density to the H(-) ion density dramatically decreases with increase of a bias voltage and the H(-) ions become dominant negative particles at the bias voltage of more than 6 V.

Spatial distribution of the charged particles and potentials during beam extraction in a negative-ion source

We report on the characteristics of the electronegative plasma in a large-scale hydrogen negative ion (H(-)) source. The measurement has been made with a time-resolved Langmuir probe installed in the beam extraction region. The H(-) density is monitored with a cavity ring-down system to identify the electrons in the negative charges. The electron-saturation current decreases rapidly after starting to seed Cs, and ion-ion plasma is observed in the extraction region. The H(-) density steps down during the beam extraction and the electron density jumps up correspondingly. The time integral of the decreasing H(-) charge density agrees well with the electron charge collected with the probe. The agreement of the charges is interpreted to indicate that the H(-) density decreasing at the beam extraction is compensated by the electrons diffusing from the driver region. In the plasmas with very low electron density, the pre-sheath of the extraction field penetrates deeply inside the plasmas. That is because the shielding length in those plasmas is longer than that in the usual electron-ion plasmas, and furthermore the electrons are suppressed to diffuse to the extraction region due to the strong magnetic field.

Acute generalized exanthematous pustulosis during the puerperal period: a case report

BACKGROUND

Acute generalized exanthematous pustulosis (AGEP) is an uncommon adverse cutaneous reaction, most commonly associated with drugs.

CASE

A 38-year-old primigravida whose labor had been induced developed erythema over her chest and abdomen. She was transferred to our department after a failed vacuum extraction, and delivered a mature infant by forceps. On day three postpartum she developed a 40.4 degrees C fever. Although ceftriaxone was administered, her fever persisted (>38 degreesC). On day six of the puerperium, diffuse non-follicular pustules appeared over her neck and trunk, and AGEP was suspected. Two days after ceftriaxone was withdrawn, the eruptions started to resolve without any medical intervention.

CONCLUSION

Once the diagnosis of AGEP has been made, the antibiotics being administered must be discontinued. If continued treatment is required, pharmacologically distinct antibiotics must be used instead to aid the rapid self-limitation of the disease.

An Early MRI Change following Reversible Hypoxic Brain Injury

We describe a patient who suffered reversible hypoxic brain injury. The initial MRI taken 3.5 hours after asphyxiation showed an abnormal lesion on DWI, but he recovered completely from coma. The presence of cytotoxic edema in the acute stage may not necessarily indicate a poor prognosis.

Irciniastatin A induces JNK activation that is involved in caspase-8-dependent apoptosis via the mitochondrial pathway

Irciniastatin A (ISA)/psymberin, a pederin-type natural product isolated from marine sponge, exhibits extremely potent and selective cytotoxicity against certain human cancer cell lines, but its molecular target and cytotoxic mechanisms are still unknown. Here we show that ISA is a potent inhibitor of protein translation, and induces apoptosis accompanied with activation of the stress-activated protein kinases via the mitochondrial pathway in human leukemia Jurkat cells. ISA potently inhibited protein translation, and induced a slow but prolonged activation of the stress-activated protein kinases, JNK and p38, at between 1h and 6h after treatment. In Bcl-x(L)-transfected cells, the activation of JNK and p38 by ISA was shortened. The same results were obtained in the cells treated with N-acetyl-L-cysteine, suggesting that the prolonged activation of JNK and p38 by ISA is mediated by reactive oxygen species generated from mitochondria. ISA strongly induced apoptosis, which was partially suppressed by the JNK inhibitor SP600125, but not by the p38 inhibitor SB202190. Apoptosis induction by ISA was partially reduced, but not suppressed by SP600125 in caspase-8-deficient Jurkat cells. These results suggest that ISA activates stress-activated kinases by a mitochondria-mediated mechanism, and that activation of JNK is required for caspase-8-dependent apoptosis.

Stevens-Johnson syndrome and toxic epidermal necrolysis due to anticonvulsants share certain clinical and laboratory features with drug-induced hypersensitivity syndrome, despite differences in cutaneous presentations

BACKGROUND

Drug-induced hypersensitivity syndrome (DIHS)/drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is characterized by late disease onset, fever, rash, hepatic dysfunction, haematological abnormalities, lymphadenopathy and often, human herpesvirus (HHV) reactivation. The diagnosis of DIHS is based on the combined presence of these findings. Anticonvulsants are a major cause of DIHS and may also cause Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). We examined whether SJS/TEN due to anticonvulsants display similar clinical and laboratory features seen in DIHS.

METHODS

Patients diagnosed with SJS or TEN due to anticonvulsants (n = 8) were examined and their clinical features and laboratory findings were compared with patients with anticonvulsant-related DIHS (n = 6).

RESULTS

Seven of the eight patients with SJS/TEN developed symptoms > 3 weeks after starting anticonvulsants. Hepatic dysfunction was present in six patients with SJS/TEN and five patients with DIHS. Leucocytosis and/or eosinophilia was noted in seven patients with SJS/TEN and four patients with DIHS. Only one patient in the SJS/TEN group had atypical lymphocytosis; this was present in four patients with DIHS. Reactivation of HHV-6 was detected in one of the four patients tested in the SJS/TEN group, although it was seen in five of the six patients with DIHS.

CONCLUSIONS

TSJS/TEN due to anticonvulsants may exhibit some clinical and laboratory features of DIHS. The nature of the cutaneous involvement should be emphasized in the diagnosis of DIHS.

Syntheses and biological evaluation of irciniastatin A and the C1-C2 alkyne analogue

Syntheses of both natural (+)- and unnatural (-)-irciniastatin A (aka psymberin) as well as a C1-C2 alkyne analogue of (+)-irciniastatin A have been achieved. The key features of the syntheses include a highly regioselective epoxide-opening reaction and a late-stage assembly of C1-C6, C8-C16, and C17-C25 fragments. (+)-Alkymberin retained a high level of cytotoxicity, whereas (-)-irciniastatin A showed almost no activity. These results suggest that (+)-alkymberin could be a useful enantio-differential probe for mode-of-action study.

Characteristics of 80 keV positive ion source for Large Helical Device

An additional beamline, BL5, equipped with four positive ion sources will be installed on Large Helical Device (LHD) in 2010. The performance of an ion source which generates 80 keV deuterium and 60 keV hydrogen beams was investigated. The structure of the ion source is based on that of a BL4 ion source on LHD. The main differences between the ion sources for the BL4 and BL5 are the acceleration voltages and the materials of plasma electrodes: copper and molybdenum, respectively. The molybdenum plasma electrode for BL5 has better performance than the copper plasma electrode of BL4. The integrated performance of the ion source for BL5 reached a value equivalent to approximately 58 A in the beam current of hydrogen positive ion at 60 keV in the beam energy.