Synthesis of an Ellagitannin Component, the Macaranoyl Group with a Tetra-ortho-Substituted Diaryl Ether Structure.

Herein, a practical synthesis of the macaranoyl group contained in ellagitannins, i.e., a C-O digallate structure with a tetra-ortho-substituted diaryl ether bond, is described. The methodology involved an oxa-Michael addition/elimination reaction between a brominated ortho-quinone monoketal and a phenol with a hexahydroxydiphenoyl moiety in the presence of 18-crown-6 under dark conditions, followed by reductive aromatization. The existence of rotamers originating from the constructed ether moiety is discussed as well.

Synthesis of diaryl ether components of ellagitannins using ortho-quinone with consonant mesomeric effects.

Methods for synthesizing C-O digallate structures, the basic unit of diaryl ether components of natural ellagitannins, are described. In the designed building block derived from gallic acid, consonantly overlapped mesomeric effects enhanced its electrophilicity. This building block demonstrated substantial reactivity to improve the synthesis of dehydrodigalloyl, tergalloyl, and valoneoyl groups.

Subspace mapping of the three-dimensional spectral receptive field of macaque MT neurons.

Neurons in the middle temporal (MT) visual area are thought to represent the velocity (direction and speed) of motion. Previous studies suggest the importance of both excitation and suppression for creating velocity representation in MT; however, details of the organization of excitation and suppression at the MT stage are not understood fully. In this article, we examine how excitatory and suppressive inputs are pooled in individual MT neurons by measuring their receptive fields in a three-dimensional (3-D) spatiotemporal frequency domain. We recorded the activity of single MT neurons from anesthetized macaque monkeys. To achieve both quality and resolution of the receptive field estimations, we applied a subspace reverse correlation technique in which a stimulus sequence of superimposed multiple drifting gratings was cross-correlated with the spiking activity of neurons. Excitatory responses tended to be organized in a manner representing a specific velocity independent of the spatial pattern of the stimuli. Conversely, suppressive responses tended to be distributed broadly over the 3-D frequency domain, supporting a hypothesis of response normalization. Despite the nonspecific distributed profile, the total summed strength of suppression was comparable to that of excitation in many MT neurons. Furthermore, suppressive responses reduced the bandwidth of velocity tuning, indicating that suppression improves the reliability of velocity representation. Our results suggest that both well-organized excitatory inputs and broad suppressive inputs contribute significantly to the invariant and reliable representation of velocity in MT.

Emergent reaction-diffusion phenomena in capillary tubes.

Pattern formation in the Belousov-Zhabotinsky reaction experiments carried out by filling capillary glass tubes with catalyst-immobilized gel for the reaction is reported. Under unperturbed and oscillatory conditions, helicoidal waves appear spontaneously. Quantitative structural data of those helices are obtained by devising an optical tomography technique for extracting rotationally symmetric structures from time-lapse data. Space-time representation of the catalyst oxidation reveals wave transmission phenomenon that is studied further by numerical simulations of a reduced spatial model.

Forty-three cases of obturator hernia.

BACKGROUND: Obturator hernia is a relatively rare pelvic hernia and usually occurs in elderly, thin, multiparous women. Because symptoms are nonspecific, the diagnosis is often delayed until laparotomy is performed form to treat bowel obstruction. METHODS: Forty-three patients with obturator hernia undergoing surgery at Tokyo Metropolitan Geriatric Hospital were divided retrospectively into two groups (group A = 23 patients from 1968 to 1986 before computed axial tomography [CAT] was developed; group B = 20 patients from 1987 to 1999 after CAT). Preoperative diagnosis, operative procedures, and postoperative course were reviewed and compared between the 2 groups. RESULTS: Preoperative diagnostic accuracy was significantly higher in group B at 80.0% (16 of 20 patients) than in group A at 43.5% (10 of 23 patients) (P = 0.0146). Rate of gut resection and mortality were significantly lower in group B at 25.0% (4 of 20) and 5.0% (1 of 20) than in group A at 52.2% (12 and 23) and 30.4% (7 of 23) (P = 0.0295 and P = 0.0385, respectively). CONCLUSIONS: The use of pelvic CAT in cases of suspected obturator hernia significantly enhances preoperative diagnostic accuracy and helps to decrease both intestinal resection rate and surgical mortality.

[beta-lactamase-producing activity and antimicrobial susceptibility of major pathogenic bacteria isolated from clinical samples. Japan beta-lactamase Research Group].

beta-Lactamase production and susceptibility to an assortment of antimicrobial agents were examined in 9,483 strains of organisms isolated from clinical materials obtained from inpatients and outpatients at 104 institutions throughout Japan from December 1999 to February 2000. The organisms were Staphylococcus aureus, 1,369 strains, including 847 methicillin-resistant (MRSA) strains; Enterococcus faecalis, 735 strains; Enterococcus faecium, 302 strains; Moraxella (Branhamella) catarrhalis, 730 strains; Haemophilus influenzae, 1,142 strains; Escherichia coli, 1,276 strains; Klebsiella pneumoniae, 1,058 strains; Enterobacter cloacae, 772 strains; Serratia marcescens, 847 strains; and Pseudomonas aeruginosa, 1,252 strains. The 23 antimicrobial agents used were ampicillin, sulbactam/ampicillin, clavulanic acid/amoxicillin, oxacillin, piperacillin, cefazolin, cefotiam, cefmetazole, cefoperazone, sulbactam/cefoperazone, cefotaxime, ceftazidime, cefepime, cefpodoxime, imipenem, gentamicin, arbekacin, clarithromycin, minocycline, chloramphenicol, vancomycin, teicoplanin, and levofloxacin. Antimicrobial agents appropriate for each organism were used. Among S. aureus strains, 61.9% were MRSA, and 62.3% were positive for beta-lactamase. Among the MRSA strains, none was resistant to vancomycin or teicoplanin, and only 3% were resistant to arbekacin. There was no vancomycin resistance in the Enterococcus strains. Only 0.1% of E. faecalis strains were ampicillin-resistant. Among the M. catarrhalis strains, 97.5% produced beta-lactamase, while among the H. influenzae strains, 8.5% produced beta-lactamase and 14.5% were beta-lactamase-negative and ampicillin-resistant (BLNAR). Among the Enterobacteriaceae and P. aeruginosa strains, there were 20 (E. coli; 7/1,276, K. pneumoniae; 13/1,058) that produced extended-spectrum beta-lactamases (ESBLs), and 11 that produced class B beta-lactamases. Multiple drug resistance was advanced in every species, and organisms resistant to 7 or more common antimicrobial agents were isolated. The best combination of antimicrobial agent and beta-lactamase inhibitor was sulbactam/cefoperazone. Sulbactam/cefoperazone, cefepime, and imipenem still have excellent antimicrobial activity. Rates of resistance to each antimicrobial agent differed more among institutions than among geographical regions.