Contrasting patterns of nitrogen release from fine roots and leaves driven by microbial communities during decomposition

Leachate from decaying root and leaf litter plays crucial roles in soil biogeochemical processes in forest ecosystems. Unlike for leaf litter, however, the chemical composition and microbial community of root litter leachate are poorly understood. We hypothesized that both leachate nitrogen (N) composition and microbial communities differ between plant organs and decomposition stages and that leachate composition affects microbial community composition. We conducted a 2.5-year laboratory incubation using root and leaf substrate from Cryptomeria japonica and Chamaecyparis obtusa. We monitored the N forms released and used metabarcoding to characterize the microbial communities. Leachate N accounted for 40 % and 30 % of net N losses from C. japonica and C. obtusa roots, respectively; the remainder was probably lost in gaseous forms. In contrast, leaves absorbed N during the incubation regardless of tree species. The predominant N form in root leachate was nitrate (NO₃^-); cumulative NO₃^- quantity was 22.6 and 25.5 times greater in root than in leaf leachate for C. japonica and C. obtusa, respectively. A nitrifying bacterium was selected as the indicator taxon in root substrates, whereas many families of N-fixing bacteria were selected in leaf substrates. At the end of the incubation period, bacterial taxonomic diversity was high in both organs from both tree species, ranging from 177 to 339 taxa and increasing with time. However, fungal diversity was low for both organs (72 to 155 taxa). Shifts in bacterial community structure were related to NO₃^- concentration and leachate pH, whereas shifts in fungal community structure were related to leachate pH. These results suggest that the contrasting N dynamics of root and leaf substrates are strongly affected by the characteristics of and the microbes recruited by their leachates. Understanding organ-specific litter N dynamics is indispensable for predicting N cycling for optimal management of forest ecosystems in a changing world.

Volt-per-Ångstrom terahertz fields from X-ray free-electron lasers

The electron linear accelerators driving modern X-ray free-electron lasers can emit intense, tunable, quasi-monochromatic terahertz (THz) transients with peak electric fields of V Å-1 and peak magnetic fields in excess of 10 T when a purpose-built, compact, superconducting THz undulator is implemented. New research avenues such as X-ray movies of THz-driven mode-selective chemistry come into reach by making dual use of the ultra-short GeV electron bunches, possible by a rather minor extension of the infrastructure.

Assessment of the potential for pathogen dispersal during high-flow nasal therapy

High-flow nasal therapy is increasingly used in hospitals because of its effectiveness and patient comfort. However, pathogens in the patient's nasal and oral cavities may be dispersed by forced air. This study aimed to investigate the risk of pathogen dispersal during high-flow nasal therapy. Liquid and bacterial dispersal were assessed via in-vitro experimental set-ups using a manikin. Thickened water or fresh yeast solution mimicked saliva and nasal mucus secretions. Dispersal was limited to the proximal area of the face and nasal cannula, suggesting that high-flow nasal therapy does not increase the risk of droplet and contact infection.

Pulse- and field-resolved THz-diagnostics at 4 t h generation lightsources

Multi-color pump-probe techniques utilizing modern accelerator-based 4th generation light sources such as X-ray free electron lasers or superradiant THz facilities have become important science drivers over the past 10 years. In this type of experiments the precise knowledge of the properties of the involved accelerator-based light pulses crucially determines the achievable sensitivity and temporal resolution. In this work we demonstrate and discuss the powerful role pulse- and field-resolved- detection of superradiant THz pulses can play for improving the precision of THz pump - femtosecond laser probe experiments at superradiant THz facilities in particular and at 4th generation light sources in general. The developed diagnostic scheme provides real-time information on the properties of individual pulses from multiple accelerator based THz sources and opens a robust way for sub femtosecond timing. Correlations between amplitude and phase of the pulses emitted from different superradiant THz sources furthermore provide insides into the properties of the driving electron bunches and is of general interest for the ultra-fast diagnostics at 4th generation light sources.

Reconstruction of root systems in Cryptomeria japonica using root point coordinates and diameters

We developed simple algorithms for reconstructing tree root system architecture using only the root point coordinate and diameter, which can be systematically obtained without digging up the root systems. Root system architecture (RSA) is strongly related to various root functions of the tree. The aim of this study was to develop a three-dimensional (3D) RSA model using systematically obtained information on root locations and root diameters at the locations. We excavated root systems of Cryptomeria japonica and systematically obtained XYZ coordinates and root diameters using a 10-cm grid. We clarified the patterns of the root point connections and developed a reconstructed root system model. We found that the root diameters farther from the stump centre are smaller. Additionally, we found that the root lengths of the segments running between the base and the connected root point were smaller than those of other root segments, and the inner angle between the base and the stump and between the base and the connected root point was narrower than for the other pairs. The new RSA model developed according to these results had average accuracies of 0.64 and 0.80 for estimates of total volume and length, respectively. The developed model can estimate 3D RSA using only root point data, which can be obtained without digging up root systems. This suggests a wide applicability of this model in root function evaluation.

Free-living nematodes associated with pine cones of Pinus thunbergii and P. taeda at Japanese coastal and inland forest sites

We surveyed the distribution of nematodes in 56 cones of Pinus thunbergii collected from both live branches and on the forest floor in three coastal and inland habitats and in 11 cones of P. taeda collected at different heights. We identified 47 nematodes to family or genera by analysis of an 18S small subunit rRNA gene sequence. The frequencies of occurrence of free-living cone nematodes were 97% in coastal P. thunbergii, 92% in inland P. thunbergii, and 82% in P. taeda. Phylogenetic analysis assigned the nematodes to four clades with high bootstrap values. Nine sequences that were found only in cones on live branches were clustered with Panagrobelus stammeri and an unknown Panagrobelus sp. Our results imply that nematodes are commonly associated with cones in pine forest ecosystems and that a capacity for anhydrobiosis may be a key to surviving above-ground.

Leachate from fine root litter is more acidic than leaf litter leachate: A 2.5-year laboratory incubation

Some tree species increase fine root production under soil acidification, thus changing the balance of litter input from leaves and roots. Litter leaches a significant amount of acidic materials during its decomposition, which might facilitate soil acidification. In this context, we focused on dissolved organic matter (DOM) as the major component of acidic materials. We hypothesized that both the quality and quantity of DOM, which control its function (i.e., proton supply), differ between leaf and root litter. To test this hypothesis, we conducted a 2.5-year laboratory incubation experiment using fresh fine roots and fresh green leaves as litter of two coniferous species (Cryptomeria japonica and Chamaecyparis obtusa) and investigated the leachate pH and DOM composition based on the optical properties. After the early stage of decomposition when flash leaching of DOM converged, the amount of dissolved organic carbon (DOC) leached from roots increased again and leachate pH declined. In contrast, DOC concentrations continued to decrease in leaf leachates during the incubation period, and the pH decrease was not as striking as that of root leachates. Optical properties (ultraviolet visible absorption and fluorescence) of DOM revealed that humic-like substances in DOM played a central role in the acidic pH of root leachates. The total amount of protons released from roots of C. japonica and C. obtusa is about 13 and 18 times higher, respectively, than that from leaves. These results imply that the increase of fine root biomass may induce a positive plant-soil feedback in acidic soils, affecting soil biogeochemical functions of terrestrial ecosystems.

Calculation procedures to estimate fine root production rates in forests using two-dimensional fine root data obtained by the net sheet method

Several recent studies have used the net sheet method to estimate fine root production rates in forest ecosystems, wherein net sheets are inserted into the soil and fine roots growing through them are observed. Although this method has advantages in terms of its easy handling and low cost, there are uncertainties in the estimates per unit soil volume or unit stand area, because the net sheet is a two-dimensional material. Therefore, this study aimed to establish calculation procedures for estimating fine root production rates from two-dimensional fine root data on net sheets. This study was conducted in a hinoki cypress (Chamaecyparis obtusa (Sieb. & Zucc.) Endl.) stand in western Japan. We estimated fine root production rates in length and volume from the number (RN) and cross-sectional area (RCSA) densities, respectively, for fine roots crossing the net sheets, which were then converted to dry mass values. For these calculations, we used empirical regression equations or theoretical equations between the RN or RCSA densities on the vertical walls of soil pits and fine root densities in length or volume, respectively, in the soil, wherein the theoretical equations assumed random orientation of the growing fine roots. The estimates of mean fine root (diameter <1 mm) production rates were ∼80-100 g m-2 year-1 using the empirically obtained regression equations, whereas those from the theoretical equations were ∼40-50 g m-2 year-1. The difference in the estimates was attributed to larger slope values of the empirical regression equations than those of the theoretical equations, suggesting that fine root orientation was not random in our study site. In light of these results, we concluded that fine root production rates were successfully estimated from two-dimensional fine root data on the net sheets using these calculation procedures, with the empirical regression equations reflecting fine root orientation in the study site.

Population genetic structure and Wolbachia infection in an endangered butterfly, Zizina emelina (Lepidoptera, Lycaenidae), in Japan

Zizina emelina (de l'Orza) is listed on Japan's Red Data List as an endangered species because of loss of its principal food plant and habitat. We compared parts of the mitochondrial and nuclear genes of this species to investigate the level of genetic differentiation among the 14 extant populations. We also examined infection of the butterfly with the bacterium Wolbachia to clarify the bacterium's effects on the host population's genetic structure. Mitochondrial and nuclear DNA analyses revealed that haplotype composition differed significantly among most of the populations, and the fixation index F ST was positively correlated with geographic distance. In addition, we found three strains of Wolbachia, one of which was a male killer; these strains were prevalent in several populations. There was linkage between some host mitochondrial haplotypes and the three Wolbachia strains, although no significant differences were found in a comparison of host mitochondrial genetic diversity with nuclear genetic diversity in Wolbachia-infected or -uninfected populations. These genetic analyses and Wolbachia infection findings show that Z. emelina has little migratory activity and that little gene flow occurs among the current populations.

A segmented multi-loop antenna for selective excitation of azimuthal mode number in a helicon plasma source

A flat type, segmented multi-loop antenna was developed in the Tokai Helicon Device, built for producing high-density helicon plasma, with a diameter of 20 cm and an axial length of 100 cm. This antenna, composed of azimuthally splitting segments located on four different radial positions, i.e., r = 2.8, 4.8, 6.8, and 8.8 cm, can excite the azimuthal mode number m of 0, ±1, and ±2 by a proper choice of antenna feeder parts just on the rear side of the antenna. Power dependencies of the electron density ne were investigated with a radio frequency (rf) power less than 3 kW (excitation frequency ranged from 8 to 20 MHz) by the use of various types of antenna segments, and n(e) up to ~5 × 10(12) cm(-3) was obtained after the density jump from inductively coupled plasma to helicon discharges. Radial density profiles of m = 0 and ±1 modes with low and high rf powers were measured. For the cases of these modes after the density jump, the excited mode structures derived from the magnetic probe measurements were consistent with those expected from theory on helicon waves excited in the plasma.

Effect of sapphire nitridation and group-III source flow rate ratio on In-incorporation into InGaN grown by metalorganic vapor phase epitaxy

In-composition of N-polar InGaN films on the sapphire substrate with the surface nitridation was investigated. By varying the ratio of the group-III source flow rate from 0.7 to 0.95, the In-composition and the surface morphologies of InGaN films were changed. The In-composition of N-polar InGaN films was affected by the strain relaxation and the surface morphologies.

Comparison of discrete ordinate and Monte Carlo simulations of polarized radiative transfer in two coupled slabs with different refractive indices

A comparison is presented of two different methods for polarized radiative transfer in coupled media consisting of two adjacent slabs with different refractive indices, each slab being a stratified medium with no change in optical properties except in the direction of stratification. One of the methods is based on solving the integro-differential radiative transfer equation for the two coupled slabs using the discrete ordinate approximation. The other method is based on probabilistic and statistical concepts and simulates the propagation of polarized light using the Monte Carlo approach. The emphasis is on non-Rayleigh scattering for particles in the Mie regime. Comparisons with benchmark results available for a slab with constant refractive index show that both methods reproduce these benchmark results when the refractive index is set to be the same in the two slabs. Computed results for test cases with coupling (different refractive indices in the two slabs) show that the two methods produce essentially identical results for identical input in terms of absorption and scattering coefficients and scattering phase matrices.

Establishment of recombinant hybrid-IgG/IgA immunoglobulin specific for Shiga toxin

Shiga toxin 1 produced by enterohaemorrhagic Escherichia coli is an AB(5) toxin that is involved in the life-threatening haemolytic-uraemic syndrome. The B subunits (Stx1B) are cell-binding subunits. We previously established mouse hybridoma cell line producing IgA and IgG monoclonal antibodies (mAbs) against Stx1B. Here, we cloned cDNAs encoding each of the heavy, light and joining (J) chains from the hybridoma cell lines by means of the 5' rapid amplification of cDNA ends (RACE) PCR method. Upon assignment of the variable regions of the heavy and light chains to known germline sequences, we found substantial somatic hypermutation in the complementarity-determining regions in both the IgA and IgG mAbs. We also established a hybrid-IgG/IgA heavy chain having variable regions of the IgG mAb by means of recombinant PCR methods. Upon transient expression of the hybrid-IgG/IgA heavy, IgG-associated light and J chains in COS-1 cells, the translated dimeric hybrid-IgG/IgA bound to immobilized Stx1B, as revealed on ELISA. The production of dimeric hybrid-IgG/IgA was revealed on immunoblot analysis. The dimeric hybrid-IgG/IgA inhibited the binding of digoxigenin-conjugated Stx1B to natural ligands (CD77) displayed on Burkitt's lymphoma cell line Ramos. These results indicate that the replacement of variable regions resulted in the production of more useful recombinant dimeric IgA against Stx1B.

Spatially homogeneous ferromagnetism of (Ga, Mn)As

Mn-doped GaAs is a ferromagnetic semiconductor, widely studied because of its possible application for spin-sensitive 'spintronics' devices. The material also attracts great interest in fundamental research regarding its evolution from a paramagnetic insulator to a ferromagnetic metal. The high sensitivity of its physical properties to preparation conditions and heat treatments and the strong doping and temperature dependencies of the magnetic anisotropy have generated a view in the research community that ferromagnetism in (Ga, Mn)As may be associated with unavoidable and intrinsic strong spatial inhomogeneity. Muon spin relaxation (muSR) probes magnetism, yielding unique information about the volume fraction of regions having static magnetic order, as well as the size and distribution of the ordered moments. By combining low-energy muSR, conductivity and a.c. and d.c. magnetization results obtained on high-quality thin-film specimens, we demonstrate here that (Ga, Mn)As shows a sharp onset of ferromagnetic order, developing homogeneously in the full volume fraction, in both insulating and metallic films. Smooth evolution of the ordered moment size across the insulator-metal phase boundary indicates strong ferromagnetic coupling between Mn moments that exists before the emergence of fully itinerant hole carriers.

Transverse-longitudinal coupling effect in laser bunch slicing

We report turn-by-turn observation of coherent synchrotron radiation (CSR) produced by the laser bunch slicing technique at an electron storage ring operated with a small momentum compaction factor. CSR emission was intermittent, and its interval depended strongly on the betatron tune. This peculiar behavior of the CSR could be interpreted as a result of coupling between the transverse and longitudinal motion of the electrons. This is the first observation of such an effect, which would be important not only for controlling the CSR emission but also for generating and transporting ultrashort electron bunches or electron bunches with microdensity structures in advanced accelerators.

Characterization of monoclonal immunoglobulin a and g against shiga toxin binding subunits produced by intranasal immunization

Immunoglobulin A (IgA) is considered to play a major role in protection of the mucosal surface. However, its immunological and biological properties have not been extensively studied because the production of IgA class monoclonal antibodies (mAbs) is difficult. We compared the properties of IgA and IgG mAbs against Shiga toxin B subunits (Stx1B). These mAbs were secreted from hybridomas that had been produced from mice after intranasal immunization with recombinant Stx1B and cholera toxin. The dose response curves for the binding of the IgA (clone G2G7) and IgG (clone D11C6) mAbs to immobilized Stx1B were similar, as revealed on ELISA. The majority of the IgA mAb formed dimers while the IgG mAb was monomeric, as judged by immunoblot analysis. The IgG mAb completely inhibited the binding of Stx1B to Burkitt's lymphoma cell line Ramos, while the inhibition by the IgA mAb was only partial. The IgG mAb was able to neutralize the cytotoxicity of Stx1 holotoxin towards Vero cells, whereas the IgA mAb was not. The binding affinity of each binding site was compared by means of surface plasmon resonance analysis involving a capture method, with which the binding of soluble Stx1B to immobilized mAb was detected. The association rate was similar but the dissociation rate was twofold faster in the case of the IgA mAb, resulting in twofold higher affinity of the IgG mAb. These results suggest that one can obtain high affinity IgA mAb but toxin neutralization is another challenge as to therapeutic antibodies of the IgA class.

Production of IgA monoclonal antibody against Shiga toxin binding subunits employing nasal-associated lymphoid tissue

We established an IgA monoclonal antibody (mAb) against Shiga toxin 1 B subunits (Stx1B) from mouse nasal-associated lymphoid tissues (NALT) of BALB/c mice. We have developed an improved protocol in which cross-linked Stx1B is intranasally administered together with cholera toxin. Surface IgA-positive NALT lymphocytes from mice immunized in this manner were enriched and then fused with mouse myeloma cells to produce hybridoma cells. Hybridoma culture supernatants were examined to see if they contain IgA against Stx1B and if they can inhibit carbohydrate recognition by Stx1B. For the latter purpose, we prepared carbohydrate ligands in which globotriose is present on the poly-lysine backbone. The established IgA mAb exhibited saturable and dose-dependent binding to the immobilized Stx1B. Inversely, the binding of the carbohydrate ligands to the immobilized Stx1B was inhibited by the mAb pretreatment. Immunoblotting and SDS-PAGE analysis revealed dimeric IgA. The IgA mAb inhibited the binding of digoxigenin-conjugated Stx1B to natural ligands displayed on a Burkitt's lymphoma cell line, Ramos. These results suggested that surface IgA-positive B cells in the inductive sites of the mucosal immune system in the upper respiratory tract are a potent source for producing IgA mAb against protein antigens with weak immunogenicity such as Stx1B.

Synthesis and antibacterial activity of acylides (3-O-acyl-erythromycin derivatives): a novel class of macrolide antibiotics

Introduction of an acyl group to the 3-O-position of erythromycin A derivatives instead of L-cladinose led to a novel class of macrolide antibiotics that we named "acylides". The 3-O-nitrophenylacetyl derivative TEA0777 showed significantly potent activity against not only erythromycin-susceptible Gram-positive pathogens but also inducibly macrolides-lincosamides-streptogramin B (MLS(B))-resistant Staphylococcus aureus and efflux-resistant Streptococcus pneumoniae. These results indicated that acylides have potential as next-generation macrolide antibiotics.

[Prostate cancer]

Carcinoma of the prostate constitutes a major and escalating international health problem. In many developed countries prostate cancer is the most commonly diagnosed malignancy in men, and seems to overtake lung cancer as major cause of cancer mortality. In Japan mortality of the prostate cancer is relatively low, but future incidence and mortality of the prostate cancer will be dramatically increased. Risk factors of the prostate cancer were well known as Western-type lifestyle and diet. Carcinoma of the prostate are detected early by prostatic specific antigen and systematic trans-rectal ultrasonography guided prostatic needle biopsy. Once prostate cancer has been diagnosed in a patient, histologically graded, and staged as accurately as possible, clinicians are duty bound to offer the best advice about treatment options, even though the risks and benefits of competing therapies. Radical prostatectomy and radiation therapy are known as treatment of localized prostate cancer, antiandrogen therapy is known as treatment of advanced prostate cancer. Alternative approaches utilizing, for example microable inhibitors, inhibitor of growth factors and gene therapy also hold exciting promise.

Suppression of CYP3A2 mRNA expression in the warfarin-resistant roof rat, Rattus rattus: possible involvement of cytochrome P450 in the warfarin resistance mechanism

1. The continual use of warfarin as a rodenticide has caused the development of populations of warfarin-resistant roof rat. To study the biochemical mechanism of warfarin resistance, the mRNA expression levels of the major P450 forms in the warfarin-resistant and -susceptible roof rat liver following exposure to warfarin were quantified by competitive RT-PCR. 2. The constitutive levels of CYP2C11 and CYP3A2 mRNAs in the warfarin-resistant and -susceptible roof rat were extremely low compared with those in the STD rat. In response to warfarin administration, the CYP3A2 mRNA level in the warfarin-susceptible rat increased to about 3-fold of that before the treatment, whereas in the warfarin-resistant roof rat, CYP3A2 mRNA remained at a low level. 3. The present results suggest the possibility that reduced synthesis of CYP3A2 mRNA is involved in the warfarin-resistant mechanism in the roof rat.

Expression of E-cadherin and catenins on testis tumor

E-cadherin (ECD) is a homophilic Ca(2+)-dependent adhesion molecule associated with cell-to-cell interactions and normal growth. Recent reports have suggested that decrease or loss of ECD facilitates tumor progression and/or metastasis. ECD functions in a complex called an adherens junction, which includes several other proteins including alpha- and beta-catenin. In the present study, fresh-frozen sections from 32 testis cancers, 16 seminomas and 16 non-seminomatous germ cell tumors (NSGCT), were examined immunohistochemically. E-cadherin was not expressed on normal germ cells, but expressed on 3 (18.8%) of 16 seminomas and 10 (62.5%) of 16 NSGCTs, mainly on the epithelial component of teratoma cells. alpha-Catenin was detected on 0 (0%) of 13 seminomas and 4 (25%) of 16 NSGCTs. beta-Catenin was detected on 10 (71.4%) of 14 seminomas and 13 (81.2%) of 16 NSGCTs. ECD was detected significantly more frequently on NSGCTs than on seminomas. Immunoblot analysis confirmed the expression of ECD and beta-catenin in NSGCTs. Expression of ECD and catenins may reflect the degree of differentiation and provide some information on the character of the tumor.

Effect of diadenosine tetraphosphate (AP4A) on coronary arterial microvessels in the beating canine heart

Diadenosine tetraphosphate (AP4A) can be released from activated platelets and the present study examined its effect on coronary arterial microvessels. The role of purinoceptors in the coronary microcirculation in vivo was also investigated. In open chest dogs, coronary arterioles were observed using a microscope with a floating objective. In Protocol 1, AP4A (1, 10, 100 and 1,000 micromol/L) was superfused onto the heart surface before and during the superfusion of 10 micromol/L of 8-phenyltheophylline (8-PT), a P1 purinoceptor blocker. In Protocol 2, AP4A (0.1, 1, 10, and 100 nmol x kg(-1) x min(-1)) was infused into the left anterior descending coronary artery before and during the superfusion of 10 micromol/L of 8-PT. In addition to 8-PT, 30 micromol/L of pyridoxalphosphate-6-azophenyl 2',4'-disulphonic acid (PPADS), a P2X purinoceptor blocker in Protocol 3, or 300 micromol/L of N(omega)-nitro-L-arginine (LNNA) in Protocol 4, was continuously superfused, and 4 doses of AP4A were cumulatively superfused as in Protocol 1. In Protocol 5, 10 micromol/L of alpha,beta-methylene ATP, an agonist of P2X purinoceptors, was superfused for 60 min. Superfused AP4A dilated arterioles in a dose-dependent manner. The magnitude of dilatation was greater in smaller arterioles (small vessel < or = 150 microm: 24.5+/-2.2% vs large vessel > 150 microm: 10.6+/-1.5% at a dose of 1,000 micromol/L, p<0.001). On the other hand, intraluminally applied AP4A also dilated arterioles, but no size dependency was shown. In the presence of 8-PT, vasodilatory responses to superfused and intraluminally applied AP4A were attenuated and the lower doses of AP4A constricted arterioles. This vasoconstrictor effect was not affected by PPADS. The vasodilatory effect of the higher doses of AP4A was almost abolished in the presence of LNNA. Alpha,beta-methylene ATP had no effect on coronary microvascular diameters. AP4A has bidirectional effects on coronary arterial microvessels: vasodilatory effects mediated by P1 purinoceptors and NO, which might be mediated by P2Y purinoceptors, and a vasoconstrictor effect, which is not mediated by P2X purinoceptors.

Treatment of bilateral renal cell cancer and multiple lung metastasis: nephron-sparing surgery and resection of lung tumors after interleukin-2 therapy

We report a case of bilateral renal cell cancer and multiple lung metastasis who was first treated with left radical nephrectomy and nephron-sparing surgery of the right kidney. Consecutive interleukin-2 administration achieved partial response in lung disease and residual tumors were surgically removed. The disease-free state has continued for 33 months.

Role of pertussis toxin-sensitive G protein in metabolic vasodilation of coronary microcirculation

We have previously demonstrated that pertussis toxin (PTX)-sensitive G protein (G(PTX)) plays a major role in coronary microvascular vasomotion during hypoperfusion. We aimed to elucidate the role of G(PTX) during increasing metabolic demand. In 18 mongrel dogs, coronary arteriolar diameters were measured by fluorescence microangiography using a floating objective. Myocardial oxygen consumption (MVO(2)) was increased by rapid left atrial pacing. In six dogs, PTX (300 ng/ml) was superfused onto the heart surface for 2 h to locally block G(PTX). In eight dogs, the vehicle (Krebs solution) was superfused in the same way. Before and after each treatment, the diameters were measured during control (130 beats/min) and rapid pacing (260 beats/min) in each group. Metabolic stimulation before and after the vehicle treatment caused 8.6 +/- 1. 8 and 16.1 +/- 3.6% dilation of coronary arterioles <100 microm in diameter (57 +/- 8 microm at control, n = 10), respectively. PTX treatment clearly abolished the dilation of arterioles (12.8 +/- 2. 5% before and 0.9 +/- 1.6% after the treatment, P < 0.001 vs. vehicle; 66 +/- 8 microm at control, n = 11) in response to metabolic stimulation. The increases in MVO(2) and coronary flow velocity were comparable between the vehicle and PTX groups. In four dogs, 8-phenyltheophylline (10 microM, superfusion for 30 min) did not affect the metabolic dilation of arterioles (15.3 +/- 2.0% before and 16.4 +/- 3.8% after treatment; 84.3 +/- 11.0 microm at control, n = 8). Thus we conclude that G(PTX) plays a major role in regulating the coronary microvascular tone during active hyperemia, and adenosine does not contribute to metabolic vasodilation via G(PTX) activation.

Use of miniature ultrasonic probe system for intravesical ultrasonography for transitional cell cancer of the urinary tract

OBJECTIVE

We describe the use of a miniature ultrasonic probe (MUP) system for intravesical ultrasonography for staging of urinary bladder and/or ureteral tumors.

MATERIAL AND METHODS

Seventeen patients with bladder tumors were enrolled in this study. Probes (8 F; 15 and 20 MHz) were inserted through a channel in a 22 F rigid cystoscopy sheath.

RESULTS

Using the MUP, each tumor could be scanned under simultaneous cystoscopic observation to choose the optimal probe position. However, in 4 of 17 patients optimal scanning could not be obtained because of large tumors and poor ultrasound penetration or because of tumor localization at the anterior dome which did not allow an appropriate scanning plane for staging. Of 13 evaluable patients, 5 with no interruption or folding of the low-echoic muscle layer were diagnosed as having a superficial tumor, and this was confirmed histopathologically in all but one case. All 8 cases evaluated as having invasive tumors demonstrated muscle invasion histologically.

CONCLUSION

The MUP can be more easily manipulated than a conventional probe.

Recurrence of IgA nephropathy 17 months after renal transplantation in the allograft transmitted thin basement membrane disease (TBMD) from donor

Recurrence of IgA nephropathy (IgAN) following renal transplantation has been described in 40-50% of such patients and it usually has a good outcome. We present the case of a 20-yr-old woman with IgAN who developed end-stage renal failure in 1995. In November 1996, she received a kidney from a living-related donor and was treated with tacrolimus, azathioprine and steroids. Zero- and one-hour biopsies were performed, which revealed minor glomerular abnormalities in light microscopy, thin basement membrane disease (TBMD) in electron microscopy. Eight months later she developed microscopic hematuria and proteinuria; however, the graft function was normal. Renal biopsy revealed an IgAN that is thought to be due to recurrence of the original disease.

Significance of serum-soluble CD95 (Fas/APO-1) on prognosis in renal cell cancer patients

Serum-soluble CD95 (sCD95) levels for 72 renal cell cancer patients were significantly higher than those of 17 healthy donors. Twenty-one of 72 patients had elevated (defined as more than mean of healthy donors + 2 s.d.) sCD95. The disease-specific survival rate was significantly lower in the elevated sCD95 group. Serum sCD95 level was shown to be an independent prognostic factor by univariate and multivariate analysis, indicating a possible significant role in determining treatment strategies.

Volumegraph (overlaid three-dimensional image-guided navigation). Clinical application of augmented reality in neurosurgery

OBJECTIVE

We have developed an overlaid three-dimensional image (Volumegraph)-guided navigation system that allows navigation during operative procedures. The three-dimensional image is superimposed on the patient's head and body via a semi-transparent mirror. The Volumegraph can display three-dimensional images in the air by a light beam which is based on CT/MRI.

METHOD

The system consists of a Volumegraph (thin plate of three-dimensional recorded medium), a Volumegraphscope and an original designed triangular-shaped marker system for registration. The three-dimensional data obtained from CT and MRI before the operation were processed by a computer. Such image data are applied for preoperative investigation to recognize the three-dimensional structure of organs and tumor. These reconstructed three-dimensional images were superimposed and registered at the patient's head according to a fiducial marker (registration). Then the operator can operate with this three-dimensional-image-guided navigation system.

RESULTS

Based on clinical application in 7 cases, the system was found to be advantageous because the surgical procedures could be navigated easily by augmented reality in the surgical field. Invisible parts of the surgical field were supplemented with the overlaid three-dimensional images (Volumegraph) as if it were the virtual operative field. At another time, spatial positioning and overlaid visualization by the Volumegraph was useful for identifying anatomical structures and functional location in the image.

CONCLUSION

This preliminary study of overlaid three-dimensional-image-guided navigation demonstrated its clinical usefulness. The application of augmented reality in the surgical field makes it possible to do a neurosurgical intervention easily and accurately.

Adoptive immunotherapy of patients with metastatic renal cell cancer using lymphokine-activated killer cells, interleukin-2 and cyclophosphamide: long-term results

BACKGROUND

Initial results of adoptive immunotherapy using lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2) appeared to offer promise for treating renal cell cancer (RCC). However, lower response rates were seen in subsequent trials, and the long-term results of this treatment method have not been fully reported. In this study, we examine long-term results of adoptive immunotherapy using LAK cells, IL-2, and cyclophosphamide (LAK/IL-2/CPM therapy).

METHODS

We administered 10 courses of therapy to 9 patients with advanced RCC. One patient had liver and para-aortic lymph node metastases; the others had only lung metastases. The clinical effects were initially evaluated 4 weeks after therapy and follow-up was continued for periods of 43 to 76 months.

RESULTS

The 4-week evaluation revealed 3 complete responses (CR), 3 partial responses (PR), 1 minor response (MR), 1 patient with no change in disease status (NC), and 2 patients whose disease progressed (PD). One CR patient remained apparently free of disease for 43 months. After tumors recurred in the lung of another CR patient further disease progression was suppressed by IL-2 administration until the patient died from other causes at 46 months. The third CR patient showed tumor recurrence in the lung and was re-treated with the same LAK/CPM/IL-2 therapy. Lung tumors decreased in size (PR), but the patient died due to brain metastasis 2 months after the second round of treatment. The 2 initial PR patients, as well as the MR and NC patients, developed regrowth or new metastatic lesions within 2 to 15 months following therapy. The 2 PD patients died 2 and 9 months after therapy.

CONCLUSION

Long-term effects of LAK/IL-2/CPM therapy were not correlated with the maximal response observed 4 weeks after therapy. Although LAK/IL-2/CPM therapy appears suitable for use as induction therapy in RCC, our data suggest that long-term suppression will require surgical removal of remnant tumors or more intensive maintenance therapy.

[Objective evaluation of selective peripheral denervation for spasmodic torticollis]

The authors evaluated the results of selective peripheral denervation (SPD) of posterior rami of the cervical spinal nerves and/or the accessory nerve for spasmodic torticollis. Five patients underwent seven operations in total and the results were evaluated with the modified Tsui's score which was used in the clinical trial of botulinum toxin (BTX) for torticollis in Japan. The preoperative score was 10.8 +/- 2.2 (mean +/- S.D.) and the postoperative score was 1.4 +/- 1.7. The score changes indicated the effects of the operation as "excellent" in four cases and "good" in one case. These results indicate that SPD is superior to BTX in terms of control of symptoms in spasmodic torticollis. After the initial operation, however, two patients showed the so-called "mole-hitting game phenomenon" in which normal muscles develop abnormal contraction after denervation of abnormal muscles. This forced us to perform the second operations. Although this phenomenon was first described in botulinum toxin treatment, this is probably the first report in surgically denervated cases.

Split cannula method for accurate placement of an electrode for deep brain stimulation: technical note

OBJECTIVE

We describe a "split cannula method" for accurate placement of a deep brain stimulation electrode. This method eliminates the risk of displacement of the electrode when withdrawing the outer guide cannula.

METHOD

A separate short guide cannula is covered over the distal part of a long cannula for microrecording or macrostimulation. After confirmation of the stimulation point, the short cannula is fixed with an accessory-holding device and the long cannula is pulled out. The electrode for deep brain stimulation is inserted through the short cannula. Because this cannula is much shorter than the electrode, securing the stimulation electrode at any withdrawal stage of the outer guide cannula is always possible.

RESULTS AND CONCLUSION

With this simple method, we experienced no displacement of the stimulation point during stereotactic insertion of a deep brain stimulation electrode. This method can be easily adapted to any stereotactic frame.

Ex vivo partial nephrectomy and partial kidney autotransplantation for renal pelvic carcinoma in a functionally solitary kidney: case report

A 46-year-old Japanese man was diagnosed with a left renal pelvic carcinoma and a contralateral hypoplastic kidney. The tumor was adjacent to the renal pelvis and was considered too difficult to completely resect in situ. The patient was treated by ex vivo partial nephrectomy of the left kidney followed by autotransplantation of the remaining renal segment. A pathologic evaluation revealed a transitional cell carcinoma, G2, pT3. Graft function recovered satisfactorily postautotransplantation and no significant complications developed during the postoperative period. The patient is alive and doing well 12 months postoperatively with no evidence of tumor recurrence.

Superior sagittal sinus thrombosis treated with combined local thrombolytic and systemic anticoagulation therapy

We recently encountered a patient with thrombosis of the superior sagittal sinus of an idiopathic cause. The patient was treated initially with combined local thrombolytic therapy through the burr hole over the superior sagittal sinus and systemic anticoagulant therapy. Continuous ventricular drainage and hyperbaric oxygenation therapy were used to control the increased intracranial pressure. The superior sagittal sinus was successfully recanalized. Whereas the patient suffered a complication with subacute subdural haematoma, he was successfully treated with the combination of these therapies. The rationale and approach are discussed.

Mechanisms of coronary microvascular dilation induced by the activation of pertussis toxin-sensitive G proteins are vessel-size dependent. Heterogeneous involvement of nitric oxide pathway and ATP-sensitive K+ channels

G proteins are critically important mediators of many signal transduction systems. In the present study, we investigated the effect of direct activation of pertussis toxin (PTX)-sensitive G protein (GPTX) on coronary arterial microvascular tone in 37 open-chest anesthetized dogs in vivo. Coronary arterial microvessels on the surface of the beating left ventricle were visualized by performing fluorescence coronary microangiography using an intravital microscope with a floating objective system. Microvessels were divided into two groups, small microvessels (inner diameter, < or = 130 microns) and large microvessels (inner diameter, > 130 microns). Topically applied mastoparan (G protein activator, 10, 30, and 100 mumol/L) produced homogeneous microvascular dilation in a concentration-dependent manner (10 mumol/L, 7.9 +/- 2.0%; 30 mumol/L, 10.3 +/- 2.4%; and 100 mumol/L, 16.7 +/- 4.5% in small microvessels; 10 mumol/L, 5.3 +/- 1.2%; 30 mumol/L, 9.8 +/- 2.5%; and 100 mumol/L, 15.5 +/- 3.9% in large microvessels). These dilations were reversed to constriction by pretreatment with PTX (300 ng/mL, 2 hours) in both microvessel groups. Blockade of nitric oxide production by NG-nitro-L-arginine (LNNA, 300 mumol/L) offset the mastoparan-induced dilation in large microvessels but not in small microvessels. Cosuperfusion of glibenclamide (10 mumol/L) with LNNA produced constriction of all sizes of microvessels in response to mastoparan, whereas charybdotoxin (10 nmol/L) did not affect the mastoparan effect. Pretreatment with glibenclamide alone reversed mastoparan dilation to constriction in small microvessels, whereas it only offset the dilation without producing constriction in large microvessels. We conclude that the activation of GPTX produces homogeneous coronary arterial microvascular dilation and that the underlining mechanisms of the dilation are vessel size dependent. The L-arginine-nitric oxide pathway mediates the dilation only in large microvessels, whereas ATP-sensitive K+ channel activation plays a central role in the dilation of small microvessels when GPTX is directly activated. ATP-sensitive K+ channels are also involved in the dilation of large microvessels in a synergistic fashion with nitric oxide production.

[Kinetics of peripheral blood CD34-positive cells and optimal timing of blood stem cell harvest after urological anticancer chemotherapy]

PURPOSE

We evaluated the changes in stem cells in peripheral blood and the optimal timing for harvesting peripheral blood stem cells (PBSCs) following the administration of conventional cancer chemotherapy in patients with urological malignancies.

PATIENTS AND METHODS

We evaluated the changes in PBSCs after the administration of cancer chemotherapy in 12 patients with urological malignancies (6 testis cancer, 3 bladder cancer, 3 prostate cancer) using flowcytometry analysis of CD34, a marker of blood stem cell. We evaluated the optimal timing for PBSCs harvesting following the administration of conventional cancer chemotherapy in 6 patients with urological malignancies (2 patients with testis cancer, 3 patients with prostate cancer, 1 patient with bladder cancer) using flowcytometry analysis of CD34 and granulocyte-macrophage colony-forming units (CFU-GM) counts. PBSC samples from 2 patients with prostate cancer were analyzed by the reverse transcriptase-polymerase chain reaction (RT-PCR) method to detect prostate cancer cells.

RESULTS

The percentages of CD34-positive cells tended to increase in the peripheral blood during the period of convalescence that followed the induction of marked myelosuppression produced by the cancer chemotherapy. The peak in CD34-positive cells occurred between days 15 and 31 after beginning of cancer chemotherapy. The percentage of CD34-positive cells was increased in the mononuclear cells in harvested PBSCs. The percentages of CD34-positive cells in peripheral blood and in mononuclear cells harvested from PBSCs was correlated with the CFU-GM counts in harvested PBSCs. The CFU-GM counts peaked between days 16 to 31 following cancer chemotherapy. RT-PCR detected prostate-specific antigen (PSA) mRNA expression in PBSCs obtained from 1 of the 2 patients with prostate cancer. An amount of contamination with PSA mRNA reduced as chemotherapy was repeated.

CONCLUSION

A sufficient number of PBSCs can be harvested after conventional cancer chemotherapy without the need for special cytotoxic mobilization that may be delayed the patient's treatment. RT-PCR results suggested that the harvested PBSCs should be examined for tumor cell contamination in patients with metastasis in bone marrow. If a sufficient amount of PBSCs will be harvested, the PBSC samples from the patient with bone marrow metastasis after repeated chemotherapy should be used by priority for PBSC transplantation as of today.

[Nephron sparing surgery for synchronous and asynchronous bilateral renal cell cancer. A procedure using intraoperative ultrasonography, argon beam coagulator and fibrin glue]

BACKGROUND

Bilateral renal cell cancer (RCC) is an imperative indication of nephron sparing surgery (NSS). In the present study, we examined a new modality for NSS; intraoperative ultrasonography, argon beam coagulator (ABC) and fibrin glue.

PATIENTS AND METHODS

We performed NSS against 7 kidneys in 5 patients, including 3 with synchronous and 2 with asynchronous tumors. Radical nephrectomy was performed on the contralateral kidney in 2 patients including one with asynchronous and the other with synchronous RCC.

RESULTS

To examine satellite lesions and exact tumor extent within the kidney, intraoperative ultrasound scan was performed for all cases. Intraoperative ultrasound scan was shown to be useful for the above mentioned purposes because of its high resolving power. After clamping of the renal artery and surface cooling, dissection of the kidney was done by knife holder or by ultrasonic aspirator. Hemostasis was made by figure eight sutures with chromic catgut or poliglecaprone 25 monofilament, followed by coagulation using ABC, and with fibrin glue. Duration of arterial clamp ranged 20 approximately 78 min under surface cooling. Major complication did not occur except urinary fistula in one case caused by inadequate placement of a double J ureteral catheter. Postoperative renal functions were well preserved and any additional therapy for daily life was not needed in each patient.

CONCLUSION

For performing NSS, the use of intraoperative ultrasound scan, ultrasonic aspirator, ABC and fibrin glue seemed to be useful, encouraging us to widespread its indication.