1,2-Carbopentafluorophenylation of Alkynes: The Metallomimetic Pull-Push Reactivity of Tris(pentafluorophenyl)borane.

We report the novel single-step 1,2-dicarbofunctionalization of an arylacetylene with an allylsilane and tris(pentafluorophenyl)borane [B(C6 F5 )3 ] involving C-C bond formation with C-H bond scission at the ß-position to the silicon atom of an allylsilane and B→C migration of a C6 F5 group. The 1,2-carbopentafluorophenylation occurs smoothly without the requirement for a catalyst or heating. Mechanistic studies suggest that the metallomimetic "pull-push" reactivity of B(C6 F5 )3 imparts consecutive electrophilic and nucleophilic characteristics to the benzylic carbon of the arylacetylene. Subsequent photochemical 6π-electrocyclization affords tetrafluoronaphthalenes, which are important in the pharmaceutical and materials sciences. Owing to the unique reactivity of B(C6 F5 )3 , the 1,2-carbopentafluorophenylation using 2-substituted furan proceeded with ring opening, and the reaction using silyl enolates formed a C-C bond with C-O bond scission at the silyloxy-substituted carbon.

A flavanone derivative from the Asian medicinal herb (Perilla frutescens) potently suppresses IgE-mediated immediate hypersensitivity reactions.

Perilla frutescens is a dietary leafy herb consumed as a traditional Japanese condiment as well as used for Chinese medicine with anti-inflammatory activity. Here we report a hitherto-unrecognized P. frutescens phytochemical that potently suppresses IgE-mediated type I hypersensitivity reactions. Structural analysis reveals that the purified anti-allergic compound (Perilla-derived methoxyflavanone, PDMF) is identified as 8-hydroxy-5,7-dimethoxyflavanone. PDMF significantly inhibits IgE-mediated histamine release from RBL-2H3 rat basophilic leukemia cells as compared with those seen in known P. frutescens-derived anti-inflammatory polyphenols. We also show that oral administration of PDMF not only suppresses passive cutaneous anaphylaxis, but also prevents allergic rhinitis-like nasal symptoms in a murine model of Japanese cedar pollinosis. Mechanistically, PDMF negatively regulates Akt phosphorylation and intracellular Ca2+ influx, both of which are essential for mast cell secretory granule translocation and its exocytosis upon high-affinity IgE receptor (FcεRI) cross-linking. These results represent PDMF as a new potent anti-allergic phytochemical useful for prevention of IgE-driven hypersensitivity reactions.

Bacterial Population Changes during the Degradation Process of a Lactate (LA)-Enriched Biodegradable Polymer in River Water: LA-Cluster Preferable Bacterial Consortium.

The lactate-based polyester poly[lactate (LA)-co-3-hydroxybutyrate (3HB)], termed LAHB, is a highly transparent and flexible bio-based polymeric material. There are many unknowns regarding its degradation process in riverine environments, especially the changes in bacterial flora that might result from its degradation and the identities of any LAHB-degrading bacteria. LAHB were immersed in the river water samples (A and B), and LAHB degradation was observed in terms of the weight change of the polymer and the microscopic changes on the polymer surfaces. A metagenomic analysis of microorganisms was conducted to determine the effect of LAHB degradation on the aquatic environment. The bacterial flora obtained from beta diversity analysis differed between the two river samples. The river A water sample showed the simultaneous degradation of LA and 3HB even though the copolymer was LA-enriched, suggesting preferable hydrolysis of the LA-enriched segments. In contrast, only 3HB degraded for the LAHB in the river B water sample. The linear discriminant analysis effect size (LEfSe) analysis revealed 14 bacteria that were significantly increased in the river A water sample during LAHB degradation, suggesting that these bacteria preferentially degraded and assimilated LA-clustering polymers. Our metagenomic analysis provides useful insights into the dynamic changes in microbial communities and LA-clustering polymer-degrading bacteria.

The effect of residual osteomyelitis at the resection margin in patients with surgically treated diabetic foot infection.

The appropriate antibiotic treatment of surgically resected diabetic foot osteomyelitis is controversial. We conducted a retrospective cohort study to evaluate the prognostic impact of residual osteomyelitis at the surgical margin of surgically resected diabetic foot osteomyelitis, and to assess the effectiveness of postoperative antibiotic therapy for residual osteomyelitis after surgical resection of infected bone. Of the 111 patients included in the study, 39 (35.14%) had pathologically confirmed margins positive for residual osteomyelitis. The median total duration of antibiotic treatment was 19 (range 10-134) days in patients with positive margins, whereas it was 14 (range 2-63) days in those with negative margins (P = .01). No statistically significant difference (P = .695) was found in the primary outcome of definite failure, defined as pathologically or microbiologically confirmed infection relapse at the proximal amputation site, between 3 (7.69%) of 39 patients with positive margins and 4 (5.56%) of 47 patients with negative margins. A statistically significant difference (P = .001) in the secondary outcome, definite treatment failure, or the need for more proximal amputation was found between 17 (43.59%) of 39 patients with positive margins and 11 (15.28%) of 72 patients with negative margins. Residual osteomyelitis at the pathologic margin was associated with a higher rate of treatment failure, despite the longer duration of antibiotic therapy.

Laryngeal myxoma.

Myxoma is a rare benign tumor, and occurs most commonly in the mandible and maxilla in the head and neck region. Myxoma of the larynx is extremely rare and is frequently misdiagnosed as a vocal polyp. We present the first female case of myxoma on a vocal cord and review the literature on this subject. The patient was 74 years old. She had undergone laryngomicrosurgery for a vocal cord polyp 20 years previously, but did not know the histological diagnosis. We performed laryngomicrosurgery for bilateral edematous vocal cords. Microscopic laryngoscopy demonstrated a mass in the submucosal space of the right vocal cord. The pathologic diagnosis of the mass was myxoma. Myxoma is a connective tissue tumor composed of multinucleate stellate cells suspended in an edematous, mucopolysaccharide-rich stroma. Since myxomas may infiltrate surrounding tissue, they have a high incidence of local recurrence. To prevent recurrence, myxoma should be surgically excised with surrounding normal tissue. Although no local recurrence has been detected, as myxoma is characterized by a slow growth rate, long-term follow-up is needed in this case.