High maneuverability guidewire with functionally graded properties using new superelastic alloys

Nitinol shape memory alloys (SMAs) are attracting considerable attention as core materials for medical guidewires because of their excellent flexibility and shape retention. However, since Nitinol guidewires possess low rigidity, the pushability and torquability of the guidewires are insufficient. On the other hand, although guidewires made of stainless steel have high pushability, plastic deformation occurs easily. We have developed a new class of superelastic guidewires with functionally graded properties from the tip to the end by using new SMA core materials such as Cu-Al-Mn-based or Ni-free Ti-Mo-Sn SMAs. The tip portion of the guidewire shows excellent superelasticity (SE), while the body portion possesses high rigidity. These functionally graded characteristics can be realized by microstructural control. These guidewires with functionally graded properties show excellent pushability and torquability and are considerably easier to handle than conventional guidewires with Nitinol or stainless steel cores. Moreover, a metallic catheter using a Ni-free Ti-based SMA with high biocompatibility is introduced.

Development of imaging bolometers for magnetic fusion reactors (invited)

Imaging bolometers utilize an infrared (IR) video camera to measure the change in temperature of a thin foil exposed to the plasma radiation, thereby avoiding the risks of conventional resistive bolometers related to electric cabling and vacuum feedthroughs in a reactor environment. A prototype of the IR imaging video bolometer (IRVB) has been installed and operated on the JT-60U tokamak demonstrating its applicability to a reactor environment and its ability to provide two-dimensional measurements of the radiation emissivity in a poloidal cross section. In this paper we review this development and present the first results of an upgraded version of this IRVB on JT-60U. This upgrade utilizes a state-of-the-art IR camera (FLIR/Indigo Phoenix-InSb) (3-5 microm, 256 x 360 pixels, 345 Hz, 11 mK) mounted in a neutron/gamma/magnetic shield behind a 3.6 m IR periscope consisting of CaF(2) optics and an aluminum mirror. The IRVB foil is 7 cm x 9 cm x 5 microm tantalum. A noise equivalent power density of 300 microW/cm(2) is achieved with 40 x 24 channels and a time response of 10 ms or 23 microW/cm(2) for 16 x 12 channels and a time response of 33 ms, which is 30 times better than the previous version of the IRVB on JT-60U.

Endoscopic treatment for superficial squamous cell carcinoma in the head and neck region (HNSCC)

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Background: The HNSCC are usually diagnosed at advanced stage, therefore, the prognosis is dismal. Recently we can find the superficial HNSCC by using high-resolution and magnifying endoscopy. We expect to get a good prognosis by the endscopic treatment (EMRC: Endoscopic Mucosal Resection by Cap-method/ELPS: Endoscopic Laryngo-Pharyngeal Surgery) for the superficial HNSCC. The purpose of this study is to examine the usefulness and effectiveness of endoscopic treatment for the superficial HNSCC. Methods: The superficial HNSCC means that the depth of cancer invasion is within the subepithelial layer. When we diagnose superficial HNSCC with no lymphnode metastasis, the endoscopic treatment (EMRC/ELPS) becomes the first line treatment under general-anesthesia. For those treatment cases, We examine the method of treatment, complication, pathological diagnosis and prognsis. Result: We have 130 patients (201 lesions) of the superficial HNSCC from Jan 2000 to Jan 2007. The endoscopic treatment cases were 92 (142 lesions), 87 male and 5 female, ranging in age from 40 to 86 years. Of the 92 patients, 56 (60.9%) had been treated by EMRC, 36 (39.1%) had been treated by ELPS. EMRC is good for small lesion (less than 10 mm in diameter). ELPS is suitable for large lesion. In EMRC case, a wound pain was often slight after the operation, and patient could leave the hospital in 4–5POD. In ELPS case, a wound pain was stronger than EMRC, and needed more hospital days. Major complication was not recognized both in EMRC and ELPS. Of 142 lesions which clinical assessments of the depth of cancer invasion were ep (epithelial layer) or sep (subepithlial layer), 140 lesions (98.6%) were histopathologically ep or sep. Two lesions (1.4%) were mp (proper muscular layer). Of the 92 patients, 83 are alive, 9 had been dead. There was no lymphnode metastasis, distant metastasis and local recurrent case. Forty patients of 3 years observation were accrued from Jan 2000 to Dec 2003. Of the 40 patients, 33 were alive, 7 were dead. No HNSCC patients died. The cause specific 3 years survival rate is 100%. Conclusion: The result of our trial indicated the usefulness of endoscopic treatment for superficial HNSCC and the effectiveness for improving the prognosis of HNSCC

No significant financial relationships to disclose.

Neural correlates of auditory feedback control in human

Auditory feedback plays an important role in natural speech production. We conducted a functional magnetic resonance imaging (fMRI) experiment using a transformed auditory feedback (TAF) method to delineate the neural mechanism for auditory feedback control of pitch. Twelve right-handed subjects were required to vocalize /a/ for 5 s, while hearing their own voice through headphones. In the TAF condition, the pitch of the feedback voice was randomly shifted either up or down from the original pitch two or three times in each trial. The subjects were required to hold the pitch of the feedback voice constant by changing the pitch of original voice. In non-TAF condition, the pitch of the feedback voice was not modulated and the subjects just vocalized /a/ continuously. The contrast between TAF and non-TAF conditions revealed significant activations; the supramarginal gyrus, the prefrontal area, the anterior insula, the superior temporal area and the intraparietal sulcus in the right hemisphere, but only the premotor area in the left hemisphere. This result suggests that auditory feedback control of pitch is mainly supported by the right hemispheric network.

Adenoviral-mediated overexpression of membrane-bound human FasL and human decoy Fas protect pig islets against human CD8+ CTL-mediated cytotoxicity

Pig islets are considered to be most suitable source of islets for xenotransplantation into patients with type 1 diabetes mellitus. However, cellular rejection, especially CD8+ CTL-mediated cytotoxicity, remains a formidable barrier preventing long-term xenograft survival. Our previous study demonstrated that human CD8+ CTLs were highly detrimental to xenograft cells and that this strong cytotoxicity of human CTLs was mediated mainly by the Fas/FasL apoptotic pathway. Furthermore, we exploited novel methods for inhibiting human CD8+ CTL-mediated xenocytotoxicity with overexpression of membrane-bound human FasL and human decoy Fas antigen in xenografted cells. In the present study, we assessed the cytoprotective effects of these novel inhibitory molecules overexpressed by an adenoviral-mediated system in pig islets. Isolated pig islets were transfected with adenovirus vector encoding either human decoy Fas or membrane-bound human FasL genes. Thirty percent to 60% of transfected pig islets expressed these molecules producing 60% to 88% suppression of CTL killing compared with parental pig islets. These data indicated that pig islet grafts isolated from transgenic pigs with either membrane-bound human FasL or human decoy Fas antigen genes may control the innate cellular response to xenografts, and creating a window of opportunity to facilitate xenograft survival.

Cross-species function of the pig C1 esterase inhibitor

BACKGROUND

The use of a bioartificial liver with pig cells for the treatment of fulminant hepatic failure will require research on the plasma complement regulatory proteins of the pig, because the liver produces most of the complement components and plasma complement regulatory proteins. In our previous study, the pig C1 esterase inhibitor (C1-INH), which functions as an inhibitor of the complement reaction in the first step of the classical pathway in the fluid phase, was cloned and some relevant features of the molecule were characterized, especially its cross-species regulation, in comparison with human C1-INH. In a further analysis, the species specificity of C1-INH was examined, using pig endothelial cells (PEC) and several types of sera.

MATERIALS AND METHODS

The cDNA of pig C1-INH was used to produce the membrane type pC1-INH, pC1-INH-PI, and inserted into the cloning site of pCXN2 (chicken beta actin promoter). The pCX/pCl-INH-PI plasmid was then transfected into PEC to establish stable PEC with pCl-INH-PI. The expression of the pCl-INH-PI was evaluated by a FACS analysis, and complement-dependent cell lysis with human, dog, rabbit, and mouse sera was then assessed.

RESULTS

The transfectant with pig Cl-INH-PI showed a high level of expression on PEC. The PEC transfectants showed an inhibitory effect on complement-dependent PEC lysis. Pig Cl-INH did not show the same suppressive effect for each serum. However, considering the alternative pathway activation of each serum on the pig cell membrane, it can be concluded that pCl-INH has a relatively small species restriction.

CONCLUSION

Pig Cl-INH, having a similar structure to human Cl-INH, shows a strong complement regulatory function on other species sera.

Sonographic findings of acute appendiceal diverticulitis

Preoperative images of acute appendiceal diverticulitis are rarely reported because of the difficulty of distinguishing appendiceal diverticulitis from other iliocecal diseases like acute appendicitis or cecal diverticulitis. We report a case of preoperatively diagnosed acute appendiceal diverticulitis. A 30-year-old female with a presumptive diagnosis of acute appendicitis from history and physical examination was admitted to our hospital. Ultrasound sonography showed inflamed appendiceal diverticula and inflammatory changes of the surrounding tissue. The swollen appendix was detected but its findings were slightly different from those of typical acute appendicitis in the following points. One difference was the thickened wall of the appendix, the other difference was the presence of air in the appendix. The patient underwent appendectomy and the pathological specimen revealed inflammatory changes of diverticula within the appendix.

Laparoscopically assisted total gastrectomy with jejunal pouch interposition

BACKGROUND

Jejunal pouch interposition (JPI) is known as a useful gastric replacement procedure after total gastrectomy. The JPI procedure, however, has not been applicable to laparoscopically assisted total gastrectomy (LATG) because of its technical complexity and difficulty. This study aimed to describe our modified LATG/JPI technique, and to evaluate its feasibility, safety, and early postoperative functional outcome.

METHODS

Between September 2002 and August 2003, LATG/JPI was attempted for five patients (3 men and 2 women) with early gastric cancers in the upper portion of the stomach. The mean age of the patients was 57 years, and their BMI was 21 kg/m2. Using a 5-port technique, the gastric arteries were laparoscopically clipped and divided with adequate lymphatic dissection. After completion of gastric resection, the anvil of a circular stapling device was placed in the esophageal stump. An 8-cm minilaparotomy then was performed, and the 12-cm pouch was created extracorporeally in the "reverse U" fashion. The stapled pouch-esophagostomy was performed under laparoscopic monitoring. The remainder of the procedure was accomplished under direct vision.

RESULTS

All cases were managed laparoscopically without any complications. The mean operating time was 407 min, and the blood loss was 279 ml. All the patients showed rapid and uneventful recovery. Postoperative studies, including dual scintigraphy, showed that all jejunal pouches were satisfactorily functioning.

CONCLUSIONS

This study showed LATG/JPI to be feasible and safe. With technical modifications, LATG/JPI can become a potentially effective option for improving patients' quality of life after total gastrectomy.

Cobalt-base high-temperature alloys

We have identified cobalt-base superalloys showing a high-temperature strength greater than those of conventional nickel-base superalloys. The cobalt-base alloys are strengthened by a ternary compound with the L1(2) structure, gamma' Co3(Al,W), which precipitates in the disordered gamma face-centered cubic cobalt matrix with high coherency and with high melting points. We also identified a ternary compound, gamma' Ir3(Al,W), with the L1(2) structure, which suggests that the Co-Ir-Al-W-base systems with gamma+gamma' (Co,Ir)3(Al,W) structures offer great promise as candidates for next-generation high-temperature materials.

Efficient propagation of polarization from laser photons to positrons through compton scattering and electron-positron pair creation

We have demonstrated for the first time the production of highly polarized short-pulse positrons with a finite energy spread in accordance with a new scheme that consists of two-quantum processes, such as inverse Compton scattering and electron-positron pair creation. Using a circularly polarized laser beam of 532 nm scattered off a high-quality, 1.28 GeV electron beam, we have obtained polarized positrons with an intensity of 2 x 10(4) e+ /bunch. The magnitude of positron polarization has been determined to be 73 +/- 15(stat) +/- 19(syst)% by means of a newly designed positron polarimeter.

Secretion of bacterial xenobiotic-degrading enzymes from transgenic plants by an apoplastic expressional system: an applicability for phytoremediation

In search of an effective method for phytoremediation of wastewater contaminated with organic compounds, we investigated the application of an apoplastic expressional system that secretes useful bacterial enzymes from transgenic plants into hydroponic media through the addition of a targeting signal. We constructed transgenic Arabidopsis expressing the aromatic-cleaving extradiol dioxygenase (DbfB), which degrades 2,3-dihydroxybiphenyl (2,3-DHB), and transgenic tobacco expressing haloalkane dehalogenase (DhaA), which catalyzes hydrolytic dechlorination of 1-chlorobutane (1-CB). Although crude leaf extracts of transgenic plants expressing cytoplasm-targeted degradative enzymes showed higher activity than did those from transgenic plants expressing apoplast-targeted enzymes, the hydroponic media of the latter showed 23.2 times (DbfB) and 76.4 times (DhaA) higher activity than plants containing the cytoplasm-targeted enzymes. Addition of crystalline 2,3-DHB to 100 mL of the hydroponic medium of transgenic or wild-type seedlings revealed that only medium from the transgenic Arabidopsis expressing apoplast-targeted DbfB showed rapid ring cleavage of 2,3-DHB. Transgenic tobacco expressing apoplast-targeted DhaA also resulted in the accumulation of the dehalogenation product 1-butanol in the hydroponic medium and showed a higher tolerance to 1-CB than wild-type or transgenic plants expressing cytoplasm-targeted DhaA. These results demonstrate the usefulness of the apoplastic expression of bacterial recombinant proteins in phytoremediation.

A simple technique for circular-stapled Billroth I reconstruction in laparoscopic gastrectomy

A simple surgical technique that facilitates circular-stapled Billroth I gastroduodenostomy in laparoscopic distal gastrectomy is described. After standard laparoscopic mobilization of the distal stomach, a small duodenotomy is made just distal to the pyloric ring. The anvil of a circular-stapling device, secured with a Vicryl suture, is introduced via the duodenotomy. The Vicryl suture is advanced anteriorly so that a center rod penetrates the anterior duodenal wall. The duodenum is staple-transected at this point, and the center rod is wrapped with the stapled duodenal stump by approximation of both edges using a suturing device. The circular-stapled gastroduodenostomy then is completed in a standard fashion. The authors have used this technique for three patients, and their early outcomes are promising.

Achievement of ultralow emittance beam in the accelerator test facility damping ring

For high luminosity in electron-positron linear colliders, it is essential to generate low vertical emittance beams. We report on the smallest vertical emittance achieved in single-bunch-mode operation of the Accelerator Test Facility, which satisfies the requirement of the x-band linear collider. The emittances were measured with a laser-wire beam-profile monitor installed in the damping ring. The bunch length and the momentum spread of the beam were also recorded under the same conditions. The smallest vertical rms emittance measured at low intensity is 4 pm at a beam energy of 1.3 GeV, which corresponds to the normalized emittance of 1.0x1.0(-8) m. It increases by a factor of 1.5 for a bunch intensity of 10(10) electrons. The measured data agreed to the calculation of intrabeam scattering within much better than a factor of 2.

Staple line coverage with absorbable mesh after thoracoscopic bullectomy for spontaneous pneumothorax

BACKGROUND

Thoracoscopic simple bullectomy for primary spontaneous pneumothorax (PSP) has a relatively high postoperative recurrence rate and sometimes results in postoperative air leakage. One of the reasons for postoperative recurrence is the regrowth of bullae around the staple line. Therefore, reinforcement of the visceral pleura around the staple line is a reasonable way to prevent postoperative air leaks and recurrence. This study was done to determine the efficacy in preventing postoperative air leak and recurrent pneumothorax of widely covering the staple line with absorbable mesh after thoracoscopic bullectomy.

METHODS

Wide coverage of the staple line with absorbable mesh was performed on 114 patients with PSP. These patients were retrospectively compared with 126 patients who underwent thoracoscopic simple bullectomy alone.

RESULTS

The postoperative duration of chest drainage in the coverage group (mean, 1 day; range, 0-5) was significantly shorter than that in the simple bullectomy group (mean, 3 days; range 0-20). A prolonged air leak (>7 days) occurred in six patients in the simple bullectomy group, but there were no such leaks in the coverage group. Recurrent pneumothorax occurred in three patients (2.6%) in the coverage group and 12 patients (9.5%) in the simple bullectomy group.

CONCLUSION

Wide coverage of the staple line with absorbable mesh is effective in preventing postoperative air leak and in decreasing the recurrence rates of PSP.

Development of medical guide wire of Cu-Al-Mn-base superelastic alloy with functionally graded characteristics

A new type of medical guide wire with functionally graded hardness from the tip to the end was developed with the use of Cu-Al-Mn-based alloys. The superelasticity (SE) of the Cu-Al-Mn-based alloys in the tip is drastically improved by controlling the grain size, whereas the end of the wire is hardened using bainitic transformation by aging at around 200-400 degrees C. Therefore, the tip of the guide wire shows a superelasticity and its end has high stiffness. This guide wire with functionally graded characteristics shows excellent pushability and torquability, superior to that of the Ni-Ti guide wire.

Divergence of mobile genetic elements involved in the distribution of xenobiotic-catabolic capacity

Bacteria adapt rapidly to environmental stimuli, such as exposure to xenobiotics. Mobile genetic elements (MGEs) play a major role in such bacterial adaptation, via the dispersal of catabolic capacity; and, in fact, genes that encode the degradation enzymes for xenobiotics are often located on MGEs. The list of reported catabolic MGEs keeps growing as researchers continue to isolate and characterize xenobiotic degraders and the corresponding catabolic genes. Major catabolic MGEs include (conjugative) plasmids, transposons, and conjugative transposons. Catabolic transposons can be divided into class I elements (composite transposons) and class II elements (Tn 3 family transposons). This review includes a comprehensive list of naturally occurring discrete catabolic MGEs, together with a brief description for each. While MGEs are often rather large, genome-wide or large-scale sequence analyses have provided useful information on the whole genetic structure of MGEs, with clues to their function (transfer, maintenance, catabolism, etc.) and behavior in a complex natural environment. This review also gives an insight into MGE functions, based on the complete sequencing of several catabolic plasmids and two Pseudomonas genomes.

Polarimetry of short-pulse gamma rays produced through inverse Compton scattering of circularly polarized laser beams

We have developed a polarimetry of ultrashort pulse gamma rays based on the fact that gamma rays penetrating in the forward direction through a magnetized iron carry information on the helicity of the original gamma rays. Polarized, short-pulse gamma rays of (1.1+/-0.2)x10(6)/bunch with a time duration of 31 ps and a maximum energy of 55.9 MeV were produced via Compton scattering of a circularly polarized laser beam of 532 nm off an electron beam of 1.28 GeV. The first demonstration of asymmetry measurements of short-pulse gamma rays was conducted using longitudinally magnetized iron of 15 cm length. It is found that the gamma-ray intensity is in good agreement with the simulated value of 1.0x10(6). Varying the degree of laser polarization, the asymmetry for 100% laser polarization was derived to be (1.29+/-0.12)%, which is also consistent with the expected value of 1.3%.