Ibudilast (3-isobutyryl-2-isopropylpyrazolo[1,5-a]pyridine) is a nonselective inhibitor of cyclic nucleotide phosphodiesterase (PDE). It is widely used in Japan for improving prognosis and relieving symptoms in patients suffering from ischemic stroke or bronchial asthma. These clinical applications are based on the properties of ibudilast that inhibit platelet aggregation, improve cerebral blood flow and attenuate allergic reactions. The inhibition of platelet aggregation and vasodilatation by ibudilast may be due to synergistic elevation of intracellular cyclic nucleotides and release of nitric oxide (NO) or prostacyclin from endothelium, rather than direct inhibition of PDE5 or PDE3. Another important property of ibudilast is its antiinflammatory activity possibly associated with potent inhibition of PDE4. Combined with its relaxing effects on bronchial smooth muscle, antiinflammatory actvity of ibudilast could favorably influence pathophysiology of asthma by antagonizing chemical mediators triggering asthmatic attacks. Ibudilast was also reported to significantly attenuate inflammatory cell infiltration in the lumbar spinal cord in an animal model of encephalomyelitis. Future investigations should include effects of ibudilast on inflammatory reactions between endothelium and blood cells, which may initiate the development of atherosclerosis.

Takayasu arteritis is a chronic vasculitis, mainly involving the aorta and its main branches as well as the coronary and pulmonary arteries, causing stenosis and/or obstruction due to thrombus formation or dilatation due to aneurysmal formation and/or rupture of the involved arteries. These characteristic anomalies resulted from ischemia of retinal arteries due to the obstruction of cervical vessels. In Western countries this disease is also known as “pulseless disease,” because the pulse is frequently absent due to the obstruction of subclavian or brachial arteries. The pathogenesis of this morbid condition is still unknown. Epidemiologically, it is found mostly in female patients and is more prevalent in Asian and Latin American countries. Affected areas consist of a mixture of both active, productive inflammatory lesions, and old fibrous lesions. Autoimmune processes stimulated by viral infection and other unknown causative factors may play an important role under these pathophysiological conditions because HLA analysis revealed a statistically significant high frequency of haplotype A24‐B52‐DR2 in these patients in Japan. Documentation of atherosclerotic complications in young female patients with Takayasu arteritis who are generally free from traditional atherosclerosis risk factors may be clinical evidence that inflammation is indeed an important risk factor in atherogenesis.

Yttrium oxyfluoride (YOF) ceramics are expected to be one of the attractive plasma-resistant materials for semiconductor production equipment. In this study, dense YOF ceramics were fabricated by hot pressing using YOF powder, and their physical, mechanical, and thermal properties were characterized. Moreover, behavior against fluorine-plasma exposure was investigated. The results suggest that the YOF ceramics showed excellent mechanical and thermal properties, and superior resistance for fluorine-plasma exposure to Y 2 O 3 ceramics.

An yttrium oxyfluoride (YOF) protective material was developed for the inner wall of plasma process equipment. Using microwave-excited surface-wave high-density plasma equipment, the chemical stability of the obtained YOF films was evaluated by exposure to H2/Ar, N2/Ar, NH3/Ar, O2/Ar, and NF3/Ar plasmas. The YOF film surface was stable against these plasmas containing hydrogen, nitrogen, oxygen, and fluorine. Especially, the stability of YOF against fluoridation was better than that of Y2O3, which is currently widely used as the protective material in plasma process chambers.

Sixty-four patients with Takayasu arteritis and 317 healthy individuals in the Japanese population were examined for HLA-A, -B and -C alleles by serological typing and for HLA-DR, DQ and DP alleles by DNA typing using PCR/SSOP analysis. The frequencies of HLA-Bw52, DRB1*1502, DRB5*0102, DQA1*0103, DQB1*0601 and DPB1*0901 alleles were significantly increased and the frequencies of HLA-Bw54, DRB1*0405, DRB4*0101, DQA1*0301, DQB1*0401 alleles were significantly decreased. Strong linkage disequilibria among the increased alleles and among the decreased alleles were evident in the Japanese population. Therefore, the combination or haplotype of HLA-Bw52-DRB1*1502-DRB5*0102-DQA1*0103-DQB1*0601 -DPA1*02-DPB1*0901 may confer susceptibility to Takayasu arteritis while another combination or haplotype of HLA-Bw54-DRB1*0405-DRB4*0101-DQA1*0301-DQB1++ +*0401 may confer resistance to the disease. Because this is the first evidence for the association between an HLA-DP allele and Takayasu arteritis, we examined the nucleotide sequences of the DPB1*0901 allele from a patient and her healthy relatives and found no difference. The disease is therefore not caused by a mutated DPB1 gene.