Imaging phonon eigenstates and elucidating the energy storage characteristics of a honeycomb-lattice phononic crystal cavity.

We extend gigahertz time-domain imaging to a wideband investigation of the eigenstates of a phononic crystal cavity. Using omnidirectionally excited phonon wave vectors, we implement an ultrafast technique to experimentally probe the two-dimensional acoustic field inside and outside a hexagonal cavity in a honeycomb-lattice phononic crystal formed in a microscopic crystalline silicon slab, thereby revealing the confinement and mode volumes of phonon eigenstates-some of which are clearly hexapole in character-lying both inside and outside the phononic-crystal band gap. This allows us to obtain a quantitative measure of the spatial acoustic energy storage characteristics of a phononic crystal cavity. We also introduce a numerical approach involving toneburst excitation and the monitoring of the acoustic energy decay together with the integral of the Poynting vector to calculate the Q factor of the principal in-gap eigenmode, showing it to be limited by ultrasonic attenuation rather than by phonon leakage to the surrounding region.

Giant extraordinary transmission of acoustic waves through a nanowire.

Wave concentration beyond the diffraction limit by transmission through subwavelength structures has proved to be a milestone in high-resolution imaging. Here, we show that a sound wave incident inside a solid over a diameter of 110 nm can be squeezed through a resonant meta-atom consisting of a nanowire with a diameter of 5 nm equal to λ/23, where λ is the incident acoustic wavelength, corresponding to a transmission efficiency of 500 or an energy densification of ~14,000. This remarkable level of extraordinary acoustic transmission is achieved in the absence of ultrasonic attenuation by connecting a tungsten nanowire between two tungsten blocks, the block on the input side being furnished with concentric grooves. We also demonstrate that these "solid organ pipes" exhibit Rayleigh end corrections to their effective longitudinal resonant lengths notably larger than their in-air analogs. Grooves on the output side lead to in-solid directed acoustic beams, important for nanosensing.

Broadband evolution of phononic-crystal-waveguide eigenstates in real- and k-spaces.

Control of sound in phononic band-gap structures promises novel control and guiding mechanisms. Designs in photonic systems were quickly matched in phononics, and rows of defects in phononic crystals were shown to guide sound waves effectively. The vast majority of work in such phononic guiding has been in the frequency domain, because of the importance of the phononic dispersion relation in governing acoustic confinement in waveguides. However, frequency-domain studies miss vital information concerning the phase of the acoustic field and eigenstate coupling. Using a wide range of wavevectors k, we implement an ultrafast technique to probe the wave field evolution in straight and L-shaped phononic crystal surface-phonon waveguides in real- and k-space in two spatial dimensions, thus revealing the eigenstate-energy redistribution processes and the coupling between different frequency-degenerate eigenstates. Such use of k-t space is a first in acoustics, and should have other interesting applications such as acoustic-metamaterial characterization.

Vibrations of microspheres probed with ultrashort optical pulses.

We use ultrashort optical pulses to excite and detect vibrations of single silica spheres with a diameter of 5 microm placed at the surface of an acoustically mismatched substrate. In addition to the photoelastic detection of picosecond longitudinal acoustic pulses propagating inside the bulk, we detect gigahertz acoustic resonances of the sphere through probe beam defocusing. The mode frequencies are in close accord with those calculated from the elastic vibrations of a free sphere. We also record a resonant enhancement in the amplitude of specific modes of two touching spheres.

[Epidural anesthesia for a patient with catamenial pneumothorax].

Endometriosis extending into the thoracic cage or the lung might induce defect of the tissue and show catamenial symptoms, such as pneumothorax or hemothorax. These events usually occur 48 to 72 hours after menstruation. A 37-year-old woman with ten year history of recurrent catamenial pneumothorax was scheduled for removal of ovarian cyst. Since intermittent positive pressure ventilation or pneumoperitoneum might induce pneumothorax, we selected epidural anesthesia for laparotomy. Epidural cannulations were performed at Th 9/10 and L 4/5 interspaces. After administration of 2% mepivacaine (400 mg) and fentanyl (0.1 mg), the block extended from Th 6 to S 5. The surgery was done without any complication. In this case epidural anesthesia for laparotomy was useful for the patient with catamenial pneumothorax.

[General anesthesia for a patient with Cornelia de Lange syndrome].

Cornelia de Lange syndrome involves anomalies in cardio-vascular and musculo-skeletal systems, and mental retardation. In addition, a patient with this syndrome shows a peculiar look. A 22-year-old woman with Cornelia de Lange syndrome underwent general anesthesia twice. She has a small mouth, thin lips, a short neck, short limbs, and stiffness of the neck and some joints associated with slight mental retardation. She was scheduled for arthroscopy and then for rotational acetabular osteotomy and valgus osteotomy. The maximum distance between the upper and lower incisors was 34 mm, when she opened her mouth. Anesthesia was induced with sevoflurane increased slowly to 7.0% in oxygen 6 l.min-1 in both procedures. After the administration of 4% lidocaine 3.5 ml into the pharynx, orotracheal intubation was attempted, but was not successful. Then blind naso-tracheal intubation was performed successfully under spontaneous respiration under sevoflurane-oxygen inhalation. The induction of anesthesia with sevoflurane under spontaneous respiration was useful for blind naso-tracheal intubation in a case with difficult intubation such as in Cornelia de Lange syndrome.

Time of useful consciousness determination in aircrew members with reference to prior altitude chamber experience and age.

BACKGROUND: Hypoxia tolerance has been evaluated by the secondary responses to oxyhemoglobin deoxygenation: the time of useful consciousness (TUC), subjective symptoms, ventilatory responses, and cardiovascular changes. It is not clear whether the deoxygenation rate per se reflects hypoxia tolerance or how it relates to the former parameters. METHODS: In Study 1, we monitored arterial oxygen saturation (SaO2) by pulse oximetry in the nonsmoking subjects experiencing hypoxia at the simulated altitude of 25,000 ft. Male subjects were divided into two groups: junior (< or =39 yr, n = 108) and senior (> or =40 yr, n = 44). The duration from mask-off to mask-on (TUC), the duration from mask-off to the time of SaO2 of 90%(T90), the duration from 90% to 70% of SaO2(T70), and the SaO2 value at mask-on (bottom SaO2) were compared between the two groups. (In a separate, but related study, 10 medical variables were analyzed by stepwise regression to investigate the contributing factors to hypoxia tolerance in 77 other subjects, including 11 female subjects.) In study 2, 12 subjective hypoxic symptoms at 25,000 ft were compared between junior (n = 369) and senior (n = 160) groups. RESULTS: TUC was significantly longer in the junior group, but T70 was longer and bottom SaO2 was higher in the senior group. Age was adopted as a contributing variable in three out of six dependent parameters. Subjective symptoms were in the similar rank order for both groups. CONCLUSION: Pulse oximetry reconfirmed that age is a major influencing factor for acute hypoxia tolerance. This may be due not only to the physiological effect but also to the training experience to recognize hypoxic deterioration more quickly.

[Perioperative management of vagotomy for treatment of frequent syncope].

A 66-year-old man was admitted to our hospital because of frequent chest pain and loss of consciousness. He had a 6-year history of angina and has taken nitroglycerin. He had received total laryngo-pharyngoectomy with the graft by jejunum for pharyngeal cancer seven months ago. The tumor, however, recurred at the neck lymphnodes. Against the increased episodes of severe bradycardia and loss of consciousness, he was scheduled to undergo subemergent vagotomy at proximal and distal side of the cancer since the cancer surrounded the nutrition vessels of the graft. Atropine 0.25 mg i.m. and 0.25 mg i.v. were administered to treat bradycardia and hypotension in the morning of operation. As a premedication atropine 0.5 mg p.o. was given. Anesthesia was induced with midazolam 3 mg, sevoflurane 5%, nitrous oxide 8 l.min-1 in oxygen 4 l.min-1. Intubation through tracheostomy was facilitated with fentanyl 100 micrograms. When the operator touched the neck, heart rate and blood pressure decreased suddenly to 35 beats.min-1 and 62 mmHg/20 mmHg, respectively. Atropine 1 mg i.v. and ephedrine 8 mg i.v. were effective. This was the only episode during surgery. After surgery all bradycardiac episodes have gone away without atropine or any other treatment. His frequent attack of bradycardia and hypotension with syncope was due to vagal reflex by the recurrent tumor.

Thymidine phosphorylase activity and angiogenesis in gastric cancer.

Angiogenesis has an important role in the growth and metastasis of solid tumors. Several angiogenic factors have been identified, one being platelet-derived endothelial cell growth factor (PD-ECGF), which is identical to thymidine phosphorylase (dThdPase). We investigated the activity of dThdPase in 84 samples of 42 human gastric cancers, by liquid chromatography. The dThdPase activity significantly correlated to the microvessel density assessed by immunostaining to CD-31 antigen (P<0.05). Expression of dThdPase has an important role in the promotion of angiogenesis in human gastric cancer.

New animal model for human ocular toxocariasis: ophthalmoscopic observation.

BACKGROUND/AIMS: Although human ocular toxocariasis causes severe vision defect, little is known about its aetiology, diagnosis, and treatment. To develop a new animal model for human ocular toxocariasis, ophthalmological findings of fundi in Mongolian gerbils, Meriones unguiculatus, and BALB/c mice were investigated following infection with Toxocara canis. METHODS: Using an ophthalmoscope, which was specifically developed to observe the fundi of small animals, ocular changes of fundi of 20 gerbils and 11 mice were monitored after oral infection with embryonated eggs of T canis. RESULTS: Vitreous, choroidal, and retinal haemorrhages were consistently observed in Mongolian gerbils, but rarely in mice. Severe exudative lesions and vasculitis were often present in gerbils but not in mice. Migrating larvae were also frequently observed in gerbils. CONCLUSION: Mongolian gerbils are more appropriate animal model for human ocular toxocariasis than previously used experimental animal such as mice, guinea pigs, rabbits, and monkeys because of its high susceptibility of ocular infection.

Intratumoral neovascularization and growth pattern in early gastric carcinoma.

BACKGROUND: The growth pattern of early gastric carcinoma, based on a volumetric analysis, reflects biologic characteristics of the tumor. The authors investigated the microvessel density (MVD), expression of vascular endothelial growth factor (VEGF), and growth patterns in early gastric carcinoma. METHODS: Ninety-four tissue specimens resected from patients with early gastric carcinoma invading the submucosal layer were examined. Microvessel quantification was performed immunohistochemically using a monoclonal antibody against factor VIII-related antigen. VEGF expression was studied using an anti-VEGF polyclonal antibody. Growth patterns were defined as follows: Pen A type: expansively penetrating growth; Pen B type: infiltratively penetrating growth; Super type: superficially spreading growth. RESULTS: The mean MVD was 16.9 (range, 5.2-43.0). MVD was significantly higher in tumors with venous invasion (P<0.01), lymphatic vessel invasion (P<0.05), and lymph node metastases (P<0.05) compared with MVD in tumors without venous or lymphatic vessel invasion or lymph node metastases. The VEGF-positive rate of Pen A type tumors was 66.7% (18 of 27), that Pen B type was 10.0% (1 of 10), that of Super type was 19.4% (6 of 31), and that of the unclassified type was 15.4% (4 of 26). The VEGF-positive rate in patients with Pen A type tumors was significantly higher than that in patients with the other three growth patterns(P<0.01). MVD in patients with Pen A type tumors (25.9+/-9.2) was significantly higher than that in patients with Super type tumors (12.6+/-5.4) (P<0.01). Patients with Pen A type tumors had a poorer prognosis than patients whose tumors had other growth patterns (P<0.05). According to multivariate analysis, VEGF expression and lymphatic vessel invasion were significant prognostic factors. CONCLUSIONS: Pen A type gastric carcinoma tends to secrete VEGF, thus inducing tumor angiogenesis and resulting in venous invasion. Intensive follow-up is necessary for patients with Pen A type tumors, because this tumor type has a greater propensity for hematogenous metastasis.

Total gastrectomy.

Total gastrectomy with lymph node dissection is one of the standard operations for gastric malignancies without distant metastases. Surgical procedures of total gastrectomy are described with illustrations easy to understand anatomy. Practical application and survival of patients are also shown.

Prognostic value of p53 protein expression for patients with gastric cancer--a multivariate analysis.

Mutations in the p53 gene, one of the most common genetic alterations in human cancer, are implicated in tumorigenesis and tumour progression. Although p53 protein expression appears to be correlated to prognosis in patients with malignancy, its prognostic role in gastric cancer has remained controversial. We examined the clinical significance of p53 overexpression in 427 patients with gastric cancer, using multivariate analysis. Tumour sections of gastric cancer tissues from these 427 Japanese patients were stained immunohistochemically with monoclonal antibody PAb1801. The presence of p53 expression was statistically compared with clinicopathological features and post-operative survival, using univariate and multivariate analyses. p53 expression was detected in 38.6% (165 out of 427) of these gastric cancers and immunoreactivity was not observed in normal mucosa adjacent to the tumour. A higher rate of p53 detection was observed among large tumours and in those with a prominent depth of invasion, lymphatic and vascular invasion and lymph node involvement. Prognosis was significantly worse for patients with p53-positive-staining tumours. The 5-year survival rate was 62.5% for patients with p53-negative tumours and 43.3% for those with positive malignancies. p53 expression was a significant prognostic factor for node-positive gastric cancers in subjects undergoing treatment with curative resection, as assessed by Cox regression analysis. Thus, the expression of p53 was closely related to the potential for tumour advance and a poorer post-operative prognosis for patients with gastric cancer.

Laparoscopic repair of a perforated duodenal ulcer in two patients.

The laparoscopic repair of a perforated duodenal ulcer was effectively done in two patients both of whom were poor risks for surgery. One was a 39-year-old woman with a history of bronchial asthma since she was 20 years of age, while the other was a 76-year-old man with hepatocellular carcinoma, lung cancer, and diabetes mellitus. The postoperative course of these patients was uneventful. Based on these findings, the laparoscopic repair of a perforated duodenal ulcer should thus be considered as a first choice of treatment for a perforated duodenal ulcer, even in poor-risk patients.

Long-term survival of patients with stage IV gastric carcinoma.

BACKGROUND: Survival of patients with Stage IV (based on general rules established by the Japanese Research Society for Gastric Cancer) gastric carcinoma often is unfavorable. Among patients with a poor prognosis, a few do survive > 5 years. The authors examined pathologic and biologic features of tumors of long term survivors. METHODS: The authors analyzed data from 442 patients with Stage IV gastric carcinoma, including 20 surviving for > 5 years after gastrectomy (Group A) and 422 who died of gastric carcinoma within 5 years (Group B). Mutant p53 was immunohistochemically stained using the monoclonal antibody PAb1801. Proliferative activity was estimated by argyrophilic nuclear organizer region (AgNOR) staining and proliferating cell nuclear antigen (PCNA) staining. RESULTS: Group A had smaller and more localized tumors than Group B (P < 0.05 and P < 0.01, respectively). Lymphatic or venous invasion and peritoneal dissemination were less frequent in Group A than in Group B (P < 0.01). Abnormalities of p53 expression were found in 3 of the 14 tumors in Group A (21%), a value significantly lower than the 58 of 118 tumors in Group B (49%; P < 0.05). AgNOR count and percentage of PCNA labeling were not significantly different between Groups A and B. A multivariate analysis showed that lymph node dissection, liver metastasis, gastric resection, venous invasion, and tumor size were independent prognostic factors. CONCLUSIONS: Even in patients with Stage IV gastric carcinoma, radical gastrectomy and extensive lymph node dissection can lead to long term survival. The authors believe that combination analysis of pathologic features and p53 overexpression predict length of survival for patients with Stage IV gastric carcinoma.

Stimulation of interleukin-8 production by acidic polysaccharides from the root of Panax ginseng.

The root of Panax ginseng C.A. Meyer, is a well-known important Chinese traditional medicine used as a stomachic, tonic, sedative and as an elixir called Ginseng in China and Japan. The precise mechanism of the biological actions of this plant is not fully understood. In order to elucidate the immunomodulating activities of this plant, we examined the direct effects of four of its components, acidic polysaccharides isolated in previous studies, on cytokine (interleukin-8; IL-8) production by a human monocytic cell line, THP-1, and human blood monocytes in vitro, as IL-8 is a potent inflammatory cytokine involved in neutrophil chemotaxis and activation. We found that one component, ginsenan S-IIA, is a potent inducer of IL-8 production by human monocytes and THP-1 cells, and this induction is accompanied by increased IL-8 mRNA expression.

Surgical treatment and outcome for node-negative gastric cancer.

BACKGROUND: The clinicopathologic characteristics and prognosis for patients with node-negative gastric cancer have heretofore remained to be determined. METHODS: We analyzed data on 730 of our patients with node-negative gastric cancer who underwent curative gastric resection in the Department of Surgery II, Kyushu University Hospital, between 1965 and 1990, with reference to prognostic factors. The presence of lymph node metastasis was determined by means of routine hematoxylin-eosin staining of excised tissues. RESULTS: The 5-year survival rate was 91.7% and the 10-year rate was 88.5%; thus the prognosis was good for patients with node-negative gastric cancer. When the prognosis was analyzed by stratification of each clinicopathologic factor, the survival time was shorter for older patients when the size of the tumor was larger, when the tumor involved the entire stomach, and when-tissues revealed infiltrative growth, serosal invasion, and lymphatic invasion. Extensive lymph node dissection was performed for 86.6% of the patients, and for these patients the prognosis was better, with a statistical difference. In a multivariate analysis, tumor size, serosal invasion, and extensive lymph node dissection proved to be independent prognostic factors for patients with node-negative gastric cancer. CONCLUSIONS: Prophylactic lymph node dissection for patients with gastric cancer will prolong the survival time.

Improved surgical results after combining preoperative hyperthermia with chemotherapy and radiotherapy for patients with carcinoma of the rectum.

PURPOSE: The aim of this study is to evaluate long-term results of preoperative hyperthermia combined with chemotherapy and irradiation (HCR therapy) in patients with carcinoma of the rectum. METHODS: Postoperative prognoses were compared among 36 patients with carcinoma of the rectum, who were given preoperative HCR therapy followed by surgery, and 52 patients undergoing surgery alone without any preoperative therapy. RESULTS: There were significant differences in the prognosis between patients given preoperative HCR therapy plus surgery and those having surgery alone, and five-year survival rates were 91.3 and 64 percent, respectively. Particularly, for patients with tumors invading beyond the muscularis propria and/or with positive lymph node metastasis, a significantly longer survival was obtained with HCR plus surgery than in surgery alone (86.5 vs. 50.9 percent and 92.9 vs. 51.7 percent, respectively). However, no significant differences were observed in the postoperative prognosis for cases with no lymph node metastasis and/or with tumors limited to the muscularis propria between these two groups. CONCLUSIONS: These data clearly demonstrated the effectiveness of preoperative HCR therapy for improving long-term results of patients with carcinoma of the rectum, especially those demonstrating an advanced stage of disease.

Significance of routine annual esophagram for early detection of carcinoma of the esophagus.

BACKGROUND/AIMS: In order to achieve increased survival rates for patients with carcinoma of the esophagus, early detection of the disease is vital. Serial esophagrams were evaluated to clarify which interval would be effective for early detection of carcinoma of the esophagus during routine examination. MATERIALS AND METHODS: One hundred eighty-nine patients with carcinoma of the esophagus were grouped into three, according to the experience and the time of the previous roentgenograms before the definite diagnosis. RESULTS: Five patients were in Group 1, in which roentgenographic examination had been done within 12 months prior to the diagnosis. Retrospective observation revealed a slight but certain abnormal shadow at the same location as the esophageal tumor seen on the second films. In Group 2, seven had received an esophagram between 12 and 24 months before the diagnosis. In contrast to Group 1, neither abnormality nor findings indicating esophageal tumors were detected on the former x-ray films, in all seven cases. Group 2 was characterized by relatively small tumors and low stage of the disease. Mean tumor length was 4.1 +/- 2.9 cm, and three of seven were classified as Stage I and two as Stage IIA. On the other hand, most of the 177 patients in Group 3, with no previous examination of the esophagus within 24 months before the diagnosis, had far advanced disease. Mean tumor length was 6.3 +/- 2.6 cm. Only nine (5.1%) were classified as Stage I, whereas 115 (65.0%) were classified as Stage III or IV. CONCLUSION: In light of these data, for populations in which esophageal cancer frequently occurs, esophageal examination every 12 months will no doubt contribute towards the early detection of lesions.