Extracorporeal circulation and hypothermic perfusion for caval tumor thrombus complicating hepatocellular carcinoma: a case report.

A tumor thrombus complicating hepatocellular carcinoma developed in a 61-year-old male patient. Embolization of the right branch of portal vein was performed 2 weeks before operation. Curative resection of the tumor was performed on by extended hepatectomy plus in situ hypothermic perfusion of the liver and extracorporeal circulation. Postoperative course was uneventful until bile leakage occurred on the 11th postoperative day. A bile duct stenosis was diagnosed by cholangiogram, and hepaticojejunostomy was carried out. The patient recovered well without further complications. The pitfalls and technical problems encountered in this case are herein discussed.

HLA-DQ-controlled T cell response to soluble egg antigen of Schistosoma japonicum in humans.

We analysed regulatory mechanisms of the human T cell response to soluble egg antigen (SEA) of Schistosoma japonicum in vitro. SEA is a crude antigen mixture containing numerous epitopes. We obtained SEA-induced T cell lines from five patients with chronic schistosomiasis japonica, and tested their proliferative response to molecular weight fractions of SEA. Although all T cell lines showed strong responses to crude SEA, there was a heterogeneity in fraction-driven responsiveness. All but one T cell line tested failed to respond to SEA fraction I (mol. wt greater than 18 kD). One patient who was typed as HLA-DQw1/w4, did not show proliferation of CD4+ T cells to fraction I; however, a fraction I-driven helper T cell response was observed when we added HU-11 monoclonal antibody specific for HLA-DQw1/w4. This indicated that the patient had helper T cells to the fraction even though their response was suppressed. Because HLA-DQ had an effect on functional expression of suppressor T cells, it was suggested that there was epitope-specific regulation of the T cell response to SEA, and HLA-DQ-controlled immune suppression might be involved in the regulatory system in human chronic schistosome infection.

Analysis of chironomid allergens using specific T cell lines and clones in humans.

To analyze the possible major T cell recognition site(s) of chironomid antigens, we established human T cell lines and clones (CD3+ 4+ 8-) reactive to soluble extracts of the adult midge of Tokunagayusurika akamusi (TAA) and/or Chironomus yoshimatsui (CYA). All T cell lines and clones proliferated heavily in response to relatively large molecular weight fractions of TAA (MW greater than or equal to 15,000). Nine clones reactive to TAA were classified into 3 groups according to reactivity, indicating the existence of at least 3 distinct T cell recognition sites in TAA. Five T cell clones responded to both TAA and CYA, although the two chironomid antigens were serologically distinct. We conclude that T cell recognition sites of chironomid antigens are different from B cell recognition sites in humans.

Analysis of lymphocyte response to chironomid midge antigens in asthmatic and non-asthmatic individuals.

Chironomid antigens are currently one of the important allergens for bronchial asthma in Japan. We evaluated in vitro responses of peripheral blood lymphocytes (PBLs) to chironomid antigens and compared these responses with serum IgE levels. PBLs from adult asthmatic patients showed stronger proliferation in response to the extract of adult midges of Chironomus yoshimatsui compared with healthy adults. On the other hand, elevated PBL responses of child asthmatic patients to chironomid antigens were not observed. There was no significant correlation between PBL proliferation and the serum IgE level. Our results might suggest that elevated PBL proliferation in response to chironomid allergens has somehow important pathogenic roles in adult cases although this does not correlate directly with specific IgE production.

Generation and functional characterization of T cell lines and clones specific for Schistosoma japonicum egg antigen in humans.

T cell lines specific for Schistosoma japonicum egg Ag were established in vitro from patients with chronic schistosomiasis japonica, and investigated their possible immunopathologic roles by testing lymphokines production and in vitro granuloma formation assay. All lines tested had surface phenotypes of CD3+ CD4+ CD8-, and showed S. japonicum soluble egg Ag (SEA)-specific proliferation requiring HLA-DR-restricted Ag presentation. Of these fractions of SEA separated by gel filtration, Fraction II (m.w. 7,000 to 18,000) and III (m.w. 7,000) induced strong proliferation of T cell lines, whereas fraction I (m.w. 18,000+) failed to induce detectable proliferation to any T cell lines tested. One of the T cell lines was cloned by micromanipulation: two of eight clones responded only to fraction II, and six to both fractions II and III. We observed that four of eight clones tested produced IL-2 in response to SEA, and three of them were able to transfer S. japonicum egg-specific granulomatous hypersensitivity in vitro to an HLA haplo-identical individual without previous schistosome infection. These immunopathologic functions of T cell clones seemed to be activated by at least two distinct epitopes of SEA. Our present observations suggest that at least two distinct CD4+ human T cells, both of which recognize epitopes expressed on SEA molecules of less than 18 kDa, might have critical roles in granulomatous hypersensitivity to eggs of S. japonicum in humans.

Fiber circular polarizer.

A fiber circular polarizer, composed of a metal-coated fiber polarizer and a lambda/4 platelet fabricated on a birefringent fiber, has been demonstrated. The lambda/4 platelet was made by cutting a birefringent fiber to an appropriate length. The device structure was designed by stress analysis simulation using a finite element method to set the angle theta = pi/4 between the fiber polarizer axis and the birefringent fiber major axis. The 17.6-dB maximum extinction ratio was obtained when the left- and right-circularly polarized light was launched into the device. It is assumed that such a fiber circular polarizer will operate as a quasi-isolator, because the light reflected from the output, the main factor backing the light source, is eliminated.

Fabrication of single-mode fiber-type polarizer.

A simple and novel fabrication technique for a fiber-type polarizer has been developed, and the polarization characteristics of the polarizer have been investigated. The polarizer is formed from a single-mode fiber composed of a concentric core and a silica cladding having a B(2)O(3)-doped silica portion. The cladding is etched off asymmetrically by utilizing the etching-speed difference between pure silica and B(2)O(3)-doped silica in 49% HF. The Al film is subsequently evaporated onto the etched portion. The extinction ratios of polarizers with various buffer-layer thicknesses were measured at two wavelengths, lambda = 1.15 pm and lambda = 1.29 microm. The maximum measured extinction ratio was 37 dB at lambda = 1.29 microm for a 4-cm-long polarizer.

Polarization properties of single-polarization fibers.

A rigorous theoretical analysis has been presented of the stress birefringence B(s) and the polarization dispersion D(s) in single-polarization fibers. Both B(s) and D(s) vary considerably in dependence on normalized frequency nu, and the nu-value dependence of B(s) and D(s) is strongly affected by the anisotropic stress distribution in the fiber. It is shown that the experimental results agree well with the calculated ones.

Stimulated Raman generation in two-mode long-length fibers pumped by a mode-locked laser.

Single-pass Raman generation pumped by a mode-locked Nd:YAG laser has been investigated for two-mode fibers each 35 km long. From input power dependence of stimulated Raman scattering, it was found that the peak wavelength of the first Stokes jumps dramatically from 1.114 to 1.12 microm at 1.65-W input power and that total output power of the first Stokes also increases rapidly at this power for a fiber with a 1.27-microm cutoff wavelength, when the fiber is pumped at the LP(11) mode exciting condition. These experimental results can be explained by the group delay for LP(01) and LP(11) modes. The maximum interaction length and the threshold power were determined from the group delay, which showed fairly good agreement with the experimental results.

Refractive-index profiling of preform rods by a photoelastic method: application to VAD single-mode fiber preforms.

An automatic and nondestructive method for measuring the refractive-index profile of optical fiber preforms using the photoelastic effect is presented. The method is applied to single-mode fiber preforms fabricated by the VAD technique. A collimated beam of linearly polarized light is passed transversely through the preform. The transmitted light is detected with a video camera equiped with a large diameter lens, a quarter-wave plate, and an analyzer. The refractive-index profile is computed from the light intensity distribution. Excellent agreement is obtained with core diameters and profiles determined from interference microscopic observation on preform slab samples.

Transmission characteristics of VAD multimode optical fibers.

The influence of convex striations of vapor phase axial deposition (VAD) optical fibers on transmission characteristics has been analyzed. These convex striations are inherent in optical fibers made by VAD and cause refractive-index fluctuations in both radial and axial directions. The phase of the sinusoidal fluctuations in the radial direction varies periodically along the fiber axis. Numerical analysis shows that bandwidth degradation due to sinusoidal fluctuations in the radial direction can be alleviated by a periodic phase variation in the axial direction.