Inhalation of gaseous hypochlorous acid and its effect on human respiratory epithelial cells in laboratory model systems.

During the disinfection of indoor spaces using gaseous hypochlorous acid (HOCl(g)), inhalation is the most common route of exposure for humans. In this study, an artificial human respiratory tract model was exposed to 12-140 ppb HOCl(g) at an aspiration flow rate of 800 mL/s for 15 h in a 1 m3 chamber. The respiratory tract model was equipped with 5th order bronchi and all gas-contact parts were made of silicone rubber with no other chlorine-consuming substances. The concentration of HOCl(g) reaching the lung pseudo-space was approximately 47.4% of the HOCl(g) concentrations in the chamber and was calculated to be very close to zero when the chamber concentration was less than 20.5 ppb. The disappearance of HOCl(g) during inhalation is likely due to the adsorption of HOCl(g) on the gas-contact silicone rubber surfaces. The cytotoxicity of HOCl(g) on respiratory epithelial cells was also examined using human air-liquid-interface airway tissue models. Human nasal epithelium and bronchiolar epithelium were exposed to 100 ppb and 500 ppb HOCl(g) for 8 h and 5 d, respectively. No significant effects of HOCl(g) on cell viability and ciliary activity were observed in any cell type, indicating that low concentrations of HOCl(g）, less than 500 ppb, had no cytotoxic effect.

Efficient reconstruction of all-in-focus images through shifted pinholes from multi-focus images for dense light field synthesis and rendering.

Scene refocusing beyond extended depth of field for users to observe objects effectively is aimed by researchers in computational photography, microscopic imaging, and so on. Ordinary all-in-focus image reconstruction from a sequence of multi-focus images achieves extended depth of field, where reconstructed images would be captured through a pinhole in the center on the lens. In this paper, we propose a novel method for reconstructing all-in-focus images through shifted pinholes on the lens based on 3D frequency analysis of multi-focus images. Such shifted pinhole images are obtained by a linear combination of multi-focus images with scene-independent 2D filters in the frequency domain. The proposed method enables us to efficiently synthesize dense 4D light field on the lens plane for image-based rendering, especially, robust scene refocusing with arbitrary bokeh. Our novel method using simple linear filters achieves not only reconstruction of all-in-focus images even for shifted pinholes more robustly than the conventional methods depending on scene/focus estimation, but also scene refocusing without suffering from limitation of resolution in comparison with recent approaches using special devices such as lens arrays in computational photography.

Enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylic acid using a chiral N-(2-hydroxymethyl-4- pyrrolidinyl)benzamide template.

[Structure: see text] Supramolecular enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylic acid (AC) was performed in the presence of (2S,4S)-4-amino-5-chloro-2-methoxy-N-(1-ethyl-2-hydroxymethyl-4-pyrrolidinyl)benzamide (TKS159), and its stereoisomers were employed as chiral templates. The TKS template provides us with a novel hydrogen-bonding and shielding motif for enantioface-selectively binding an AC molecule. Chiral products 2 and 3 were obtained in good enantiomeric excesses (ee's) of 40% and 40%, respectively.

Analysis of the loading and hydroxylation steps in lankamycin biosynthesis in Streptomyces rochei.

The biosynthetic gene cluster of lankamycin (LM), a 14-member macrolide antibiotic, is encoded on the 210-kb linear plasmid pSLA2-L in Streptomyces rochei 7434AN4. LM contains a 3-hydroxy-2-butyl group at the C-13 position, which is different from an ethyl group in erythromycin. The following two possibilities could be considered for the origin of this starter moiety of LM biosynthesis: (i) an extra module exists in the biosynthetic gene cluster and loads an additional acetate molecule, or (ii) 3-hydroxy-2-butyrate or its equivalent is loaded and incorporated as a starter. The former possibility was eliminated by the complete sequencing of pSLA2-L, which showed no extra module. On the other hand, the latter was confirmed by incorporation of deuterium in [3-(2)H]dl-isoleucine into the C-14 position of LM. The timing of hydroxylation reactions at the C-15 and C-8 positions of LM was studied by constructing disruptants of two P450 hydroxylase genes, lkmF (orf26) and lkmK (orf37). The lkmF disruptant produced 8-deoxylankamycin, while the lkmK disruptant produced both 15-deoxylankamycin and 8,15-dideoxylankamycin. These results clearly showed that LkmF is a C-8 hydroxylase and LkmK is a C-15 hydroxylase in LM biosynthesis and in addition suggested the order of hydroxylation steps; namely, hydroxylation may occur at first at C-15 by LkmK and then at C-8 by LkmF.

Cyclization mechanism for the synthesis of macrocyclic antibiotic lankacidin in Streptomyces rochei.

The lankacidin biosynthetic gene cluster in Streptomyces rochei strain 7434AN4 was found to span 31 kb of the giant linear plasmid pSLA2-L and contain a polyketide synthase (PKS)/nonribosomal peptide synthetase (NRPS) hybrid gene (lkcA), type I PKS genes, and pyrroloquinoline quinone (PQQ) biosynthetic genes (lkcK-lkcO). Feeding of PQQ to a pqq mutant restored the lankacidin production, suggesting its crucial role in an oxidation process. However, formation of the 17-membered macrocyclic ring was not catalyzed by PQQ-dependent dehydrogenase (Orf23), but was by flavin-dependent amine oxidase (LkcE). Compound LC-KA05 isolated from an lkcE disruptant was an acyclic intermediate lacking the C2-C18 linkage. These results suggested a cyclization mechanism for the synthesis of the lankacidin macrocyclic skeleton.

Infrainguinal bypass surgery for chronic arterial occlusive disease associated with essential thrombocythemia: report of a case.

A 63-year-old man was referred to our hospital with a 3-year history of intermittent claudication, and his angiogram showed a total occlusion of the bilateral infrainguinal arteries. In addition, based on a platelet count of 172 x 10(4)/mm(3) as well as the characteristic bone marrow findings, he was diagnosed to have essential thrombocythemia. After the platelet count and aggregation response improved on administration of ranimustine and antiplatelet agents, infrainguinal bypass surgery was performed using the saphenous vein and prosthetic grafts. The bilateral grafts had been patent for 10 months postoperatively, but his discontinuance of medication caused an acute occlusion of the prosthetic graft. The graft was salvaged with a prompt thrombectomy and, now under strict medication control, he is leading an active life.

Clinical study of Japanese spotted fever and its aggravating factors.

Twenty-eight patients with Japanese spotted fever were clinically investigated. The diagnosis was determined by confirming an increase of specific antibody. All patients were treated with minocycline, and all recovered, excluding one patient with a fulminant course. Fever and exanthema were observed in all patients, and an eschar was pointed out in 20 (71%) patients. The platelet count was 10 x 10(4)/microl or lower in 8 (28%) patients. The fibrin degradation product (FDP)-level was abnormally high, 10 microg/ml or more, in 16 (57%) patients. The creatine kinase (CK) value was high in 14 of 22 patients, suggesting the presence of myositis. The leukocyte count, FDP, C-reactive protein, and soluble interleukin 2 receptor (sIL2-R) levels were significantly higher in severe cases. In the group without concomitant steroid therapy, mean times of 54.7 h and 101.4 h were required to reduce the temperature to 38 degrees C and 37 degrees C or lower, respectively, after the initiation of tetracycline treatment. There were 6 severe cases: 1 with disseminated intravascular coagulation, 2 with multiorgan failure, 1 with acute respiratory distress syndrome, and 2 with meningoencephalitis. These severe cases formed a group that required 6 or more days to initiate therapy after the onset (P < 0.005 vs non-severe group), showing that delay in diagnosis and therapy is the major cause of aggravation. In the 2 patients complicated by multiorgan failure, the sIL2-R level, produced by activated lymphocytes, was 10,000 U/ml or higher, suggesting that an sIL2-R level of more than 10,000 U/ml can be used as a marker of poor prognosis. It may be better that moderate to severe cases are treated with minocycline plus short-term steroid therapy.

Fulminant Japanese spotted fever definitively diagnosed by the polymerase chain reaction method.

A 72-year-old man was admitted to the emergency ward in our hospital on July 20, 2001, because of consciousness disturbance, fever, generalized skin eruption, and severe general weakness beginning 7 days previously. Physical examination on admission revealed marked systemic cyanosis, erythema, and purpura. Laboratory findings indicated disseminated intravascular coagulation (DIC) and multiorgan failure (platelet count, 0.9 x 10(4)/micro l; fibrin degradation product, 110 micro g/ml; C-reactive protein, 22.6 mg/dl). Soluble interleukin 2-receptor (sIL-2R) was markedly increased to 14 710 U/ml. Blood gas analysis demonstrated severe metabolic acidosis. He was diagnosed with multiorgan failure due to DIC. Administration of heparin and sodium bicarbonate was started immediately, but respiratory failure was exacerbated and systemic spasm caused by encephalitis was noted. Although he was supported by an artificial ventilator, deterioration of metabolic acidosis occurred, and the blood pressure decreased to less than 60 mm Hg. He died 5.5 h after admission. The serological test showed no positive antibody titers against Orientia tsutsugamushi, Rickettsia japonica, or Rickettsia typhi. However, a specific DNA band derived from R. japonica was detected by the polymerase chain reaction (PCR) method using a primer from a blood clot. Therefore, he was definitively diagnosed as having Japanese spotted fever. The PCR method may be markedly useful for establishing a definitive diagnosis of Japanese spotted fever during the critical stage.