Evaluation of high-stability optical beats in laser chaos by plasmonic photomixing.

The stability of optical beats in a chaotically oscillating laser is compared to that of a free-running continuous-wave laser using a highly efficient plasmonic photomixer. Using a chaotically oscillating laser diode, stable optical beats are observed over an operation current range of 60-90 mA. The optical spectra are stable even with frequent mode hopping. In contrast, optical beats in a free-running continuous-wave laser are not stable compared to those of a chaotically oscillating laser, because of intermittent hopping of the laser modes. The high stability of chaotically oscillating lasers makes these lasers promising candidates for optical pump sources in terahertz time-domain spectroscopy systems.

A new force-based objective assessment of technical skills in endoscopic sinus surgery.

We propose objectively assessing endoscopic sinus surgery (ESS) skills by measuring the force applied to a patient model. We collected data on 16 subjects performing gauze packing task using a precise human nasal model with a six-degree-of-freedom force/torque sensor. Mann-Whitney's U test was used to analyze their performance. Intermediates (ESS: 10-50 cases) used significantly greater force than students or experts (ESS: over 150 cases) at the 5 % level. Maximum force improved only among experts. These results imply that young surgeons pay too little attention to force applied to patients or tissues.

Effects of sivelestat, a new elastase inhibitor, on IL-8 and MCP-1 production from stimulated human alveolar epithelial type II cells.

PURPOSE: The alveolar epithelial cell type II (AEC-II) is itself able to amplify lung inflammation by producing inflammatory cytokines and chemokines, leading to the activation and recruitment of phagocytes. Sivelestat, a new neutrophil elastase inhibitor, has been shown to attenuate acute lung injury in animal experiments. In the current study, we assessed the effects of sivelestat on the production of chemokines from cultured A549 cells, a human AEC-II-like cell line. METHODS: A549 cells were stimulated with endotoxin or tumor necrosis factor-alpha in the presence of sivelestat (1-100 microg x ml(-1)). Culture supernatant levels of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) were determined by enzyme-linked immunosorbent assay. The expression of IL-8 and MCP-1 mRNAs in stimulated A549 cells in the presence of sivelestat (100 microg x ml(-1)) was quantified by real-time polymerase chain reaction. RESULTS: Sivelestat, at 100 microg x ml(-1) reduced the accumulation of IL-8 and MCP-1 in the culture medium. The high dose of sivelestat significantly inhibited the expression of IL-8 mRNA in A549 cells. The drug also decreased MCP-1 mRNA expression, although not significantly. CONCLUSION: These data suggest that a high dose of sivelestat regulates the production of IL-8 and MCP-1 in AEC-II.

An endoscopic sinus surgery training system for assessment of surgical skill.

The apprenticeship of procedures in endoscopic sinus surgery has several limitations, including potential risk for the patients and lack of feedback to the trainees. In this paper, we present a new surgical training system that combines a head dummy, force and position sensors: this system can be used to assess surgical skills and provide visual feedback to the trainees.

Influence of occlusal height for an implant prosthesis on the periodontal tissues of the antagonist.

The purpose of this study was to investigate a suitable occlusal height for an implant prosthesis by examining the responses of the periodontal tissues around a natural antagonist. The subjects were three Japanese females with two posterior missing teeth restored by ITI system implants (Straumann). Two kinds of experimental implant prostheses were adjusted as follows; one was adjusted in heavy clenching (HC), and the other was adjusted in light clenching (LC). The periodontal pulsation, displacement during biting an occlusal force meter and the mobility of the antagonist were measured before and one week after temporary cementing HC and LC, and one week after removal. In each prosthesis, there was no significant difference in the amounts of the pulsation and mobility of the antagonist before and one week after cementing, and one week after removal (p>0.05). The displacement of the antagonist during biting the occlusal force meter did not change much during the conditions. The results of this study suggested that an implant prosthesis adjusted not only under heavy clenching but light clenching like crown restorations for natural teeth did not affect the periodontal tissues of the antagonist in a harmful manner.

Overexpression of tumor necrosis factor-alpha diminishes pulmonary fibrosis induced by bleomycin or transforming growth factor-beta.

Tumor necrosis factor-alpha (TNF-alpha) is thought to be important in the development of pulmonary fibrosis. However, surfactant protein-C/TNF-alpha transgenic mice do not spontaneously develop pulmonary fibrosis but instead develop alveolar enlargement and loss of elastic recoil. We hypothesized that overexpression of TNF-alpha in the lung requires an additional insult to produce fibrosis. In this study we evaluated whether TNF-alpha overexpression altered the development of pulmonary fibrosis due to bleomycin or transforming growth factor-beta (TGF-beta). Either 0.2 U bleomycin or saline was administered into left lung of TNF-alpha transgenic mice and their transgene-negative littermates. To overexpress TGF-beta, an adenovirus vector containing either active TGF-beta (AdTGF-beta) or LacZ was administered at a dose of 3 x 108 plaque-forming units per mouse. Fibrosis was assessed histologically and by measurement of hydroxyproline. TNF-alpha transgenic mice tolerated bleomycin or AdTGF-beta, whereas the transgene-negative littermates demonstrated severe pulmonary fibrosis after either agent. An increase in prostaglandin E2 and downregulation of TNF receptor I expression were observed in the TNF-alpha transgenic mice. In addition, recombinant human TNF-alpha attenuated bleomycin-induced pulmonary fibrosis. TNF-alpha has a complex role in the development of pulmonary fibrosis. Endogenous TNF-alpha may be important in the development of fibrosis as indicated in other reports, but overexpression of TNF-alpha or exogenous TNF-alpha limits pulmonary fibrosis in mice.

Novel variants of murine serotonin transporter mRNA and the promoter activity of its upstream site.

Three variants of murine serotonin transporter (5-HTT) mRNA, which consist of a different exon-one (exon 1a, exon 1b or exon 1c) and the same exon-two to exon-five, were identified. The promoter region for each exon 1 (p1a, p1b and p1c, respectively), ligated to pGL-3 enhancer vector, had activities significantly higher than the empty vector in all cell lines tested except p1c in PC-12, whereas the activity of p1c was significantly lower than the others. Effects of the treatment of dibutyryl-cyclic AMP, human interferon-alpha or mouse interferon-gamma have different profiles among COS-7, PC-12, C6 glioma and immortalized rat serotonergic raphe neurons, RN46A. These three promoter regions may play a role in the transcription of the 5-HTT and could offer a model of the regulation of 5-HTT production in humans and further the pathogenesis of depression.

[Influence of occlusal contacts of implant on adjacent teeth and antagonists displacements].

This study examined the optimum occlusal contacts of implant prostheses to maintain good oral condition after treatment. Three subjects who had two contiguously missing teeth (first and second molars) were selected. The displacement path of the implant, the adjacent tooth and the antagonistic tooth during clenching were measured using the type M-3 three-dimensional tooth displacement transducer. The occlusal contacts of implant prostheses changed according to the following four conditions. A contact: the inner inclination of the upper buccal cusp, B contact: the inner inclination of the upper lingual cusp, C contact: the outer inclination of the upper lingual cusp, and ABC contact: including the above three contacts. The measurements were performed at least six months after implant surgery. In each subject, the implants and the adjacent teeth were not affected by the change of the occlusal contact of the implant prosthesis, but the opposing teeth were affected. In the case of implantation in the lower side, the opposing tooth displaced in the buccal direction with A contact and C contact, which was a different direction to that of the natural tooth. The antagonist with B contact displaced in the lingual direction, which was the same direction as that of the natural tooth. The antagonist with ABC contact displaced in the lingual or buccal direction. It is concluded that the occlusal adjustment of implants needs much care: in the case of only A contact or C contact, non-physiological distortion might occur in periodontal tissues of the opposing teeth of the implant.

The efficacy of lafutidine in improving preoperative gastric fluid property: a comparison with ranitidine and rabeprazole.

IMPLICATIONS: Acid aspiration syndrome remains a potentially critical perioperative complication. We compared lafutidine, ranitidine, and rabeprazole for reduction of preoperative gastric fluid acidity and volume in elective surgery and found that these variables were minimized with a single morning dose of lafutidine 20 mg compared with ranitidine or rabeprazole. Preoperative oral lafutidine may be an alternative to ranitidine as a prophylaxis against aspiration pneumonia.

The effects of intravenous anesthetics and lidocaine on proliferation of cultured type II pneumocytes and lung fibroblasts.

UNLABELLED: Type II pneumocytes synthesize surfactant and differentiate into type I pneumocytes to maintain the epithelium (1). Alveolar type II cell proliferation is required for reepithelization after acute lung injury (ALI) and is thought to minimize the subsequent fibrotic response (1). Keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF) are among the most potent mitogen for type II epithelial cells, but not for fibroblasts in the lung (1). These growth factors attenuate several experimental ALI models by promoting epithelial repair (2,3). Thus, KGF and HGF may be a promising therapeutic approach to ALI. Critically ill patients with ALI often receive IV anesthetics or sedatives to facilitate mechanical ventilation. Furthermore, these patients sometimes undergo bronchoscopy under local anesthesia to obtain bronchoalveolar lavage fluid or to remove respiratory secretions. Several IV and local anesthetics inhibit proliferation of various cells including epithelium (4,5). If these anesthetics impede proliferation of type II pneumocytes, this suppressive effect may be a disadvantage for alveolar reepithelization in the course of recovery from ALI. In this study, we examined the effects of midazolam, propofol, ketamine, thiopental, and lidocaine on proliferation of type II alveolar epithelial cells using in vitro culture system. Because fibroblast proliferation is a key event in late phase of ALI, inhibition of this fibroproliferation is probably beneficial. Thus, we further determined whether these anesthetics could regulate proliferation of lung fibroblasts. In the current study, rolipram was used as a positive control. In our previous preliminary experiment, we found that rolipram, a phosphodiesterase inhibitor type IV, augments spontaneous or KGF-/HGF-promoted type II cell proliferation (6). IMPLICATIONS: Midazolam, ketamine, thiopental, propofol, or lidocaine did not inhibit proliferation of cultured rat type II pneumocytes. Our findings suggest that these anesthetics do not impede alveolar reepithelization after acute lung injury.

Intramolecular Cyclizations of o-Acylbenzyllithiums. Formation of Benzocyclobuten-1-ol Derivatives and Their Thermal Isomerization.

The formation of benzocyclobutenol derivatives by intramolecular cyclizations of o-acylbenzyllithiums is described. Treatment of o-(trialkylsilylmethyl)phenyl ketones with lithium diisopropylamide (LDA) followed by quenching of the resulting benzylic carbanions with chlorotrialkylsilane resulted in stereoselective formation of the corresponding 1-trialkylsiloxy-2-(trialkylsilyl)benzocyclobutenes in good yields. Subsequently, o-acyl-m-methoxybenzyllithiums were found to work well in cyclization to benzocyclobuten-1-ol derivatives. The reaction of 2-benzoyl-3,4,5-trimethoxybenzyllithium, generated in situ by deprotonation of 6-methyl-2,3,4-trimethoxybenzophenone with LDA, with chlorotrimethylsilane afforded the corresponding 1-(trimethylsiloxy)benzocyclobutene. Cyclization of 2-pivaloyl-3-methoxybenzyllithiums, generated in situ from tert-butyl 2-methyl-6-methoxyphenyl ketones upon deprotonation with LDA, proceeded spontaneously even at -78 degrees C to give the corresponding benzocyclobuten-1-ols. We also describe the results of thermal isomerization of these 1-trimethylsiloxy-2-(trialkylsilyl)benzocyclobutenes.

Efficient Synthesis of 1-Amino-2-naphthalenecarboxylic Acid Derivatives via a Sequential Michael Addition/Enolate-Nitrile Coupling Route and Its Application to Facile Preparation of 9-Amino Analogues of Arylnaphthofuranone Lignans.

The reaction of 2-(alpha-lithioalkyl)benzonitriles, generated in situ by treatment of 2-alkylbenzonitriles with LDA in diglyme, with alpha,beta-unsaturated carboxylates and nitriles produced 1-amino-3,4-dihydro-2-naphthalenecarboxylates and carbonitriles in 54-98% yields through Michael addition of the lithio nitriles to alpha,beta-unsaturated carboxylic acid derivatives, followed by zinc iodide-promoted intramolecular enolate-nitrile coupling of the resulting enolate intermediates. The dihydronaphthalenecarboxylic acid derivatives were converted to the corresponding 1-amino-2-naphthalenecarboxylic acid derivatives in 43-99% yields on dehydrogenation with palladium on activated carbon in refluxing p-cymene. Subsequently, we showed that, by using a similar reaction sequence, 9-amino analogues of arylnaphthofuranone lignan derivatives {9-amino-4-arylnaphtho[2,3-c]furan-1(3H)-ones} could also be prepared from 2-(arylmethyl)benzonitriles and furan-2(5H)-one in good overall yields (59-61%).

Reactions of Vinyl Sulfoxides with Magnesium Amides. One-Pot Synthesis of Symmetrical and Unsymmetrical beta-(Dialkylamino) Dithioacetals.

Vinyl sulfoxides (PhSOCR(1)=CHR(2): R(1) = H, Me, or Ph; R(2) = H or Me) were treated with (dialkylamino)magnesium reagents, generated in situ from the reaction of EtMgBr with secondary amines (R(3)R(4)NH: R(3) = Et, i-Pr, or Bn; R(4) = Me, Et, or i-Pr) in refluxing Et(2)O for 1 h, and stirring at room-temperature overnight gave the corresponding symmetrical beta-(dialkylamino) dithioacetals [(PhS)(2)CR(1)CHR(2)NR(3)R(4)] in 24-84% yields. When the (diethylamino)magnesium reagent was treated with appropriate thiols (RSH; R = p-ClC(6)H(4) or Bn) prior to the interaction with phenyl vinyl sulfoxide, the corresponding unsymmetrical beta-(diethylamino) dithioacetals [(PhS)(RS)CHCH(2)NEt(2)] were produced in 63-67% yields.