Negative quantum interference between the electronic Raman scattering processes of CuO chains and CuO2 planes of heavily overdoped (Y, Ca)Ba2Cu3O(7-delta)

We found a strong X-Y anisotropy of the pair-breaking peak in the Raman scattering of heavily overdoped (Y, Ca)Ba2Cu3O(7-delta) (T(c) = 65 K). The pair-breaking peak is radically suppressed in the YY-polarized spectrum. We ascribe this anomaly to the effect of quantum interference between the Raman processes of the CuO-chain and the CuO2-plane electronic excitations that might take place as a result of the increase in the transfer matrix due to overdoping.

Tolerance mechanism of the ethanol-tolerant mutant of sake yeast

Several ethanol-tolerant mutants have been bred from industrial sake yeasts, but the mechanism of ethanol tolerance in these mutants has not been elucidated. After the determination of the entire genome sequence of Saccharomyces cerevisiae, various methods to monitor the whole-gene expression of the yeast have been developed. In this study, we used a commercially available nylon membrane on which virtually every gene of S. cerevisiae was spotted to compare expression profiles between the ethanol-tolerant mutant and its parent sake yeast to investigate the mechanism of ethanol tolerance in this mutant. As a result, we found that several genes were highly expressed only in the ethanol-tolerant mutant but not in the parent strain. These genes were known to be induced in cells that were exposed to various stresses, such as ethanol, heat, and high osmolarity, or at the stationary-phase but not at the log-phase. In the ethanol-tolerant mutant, the expression level of these stress-responsive genes was further increased after exposure to ethanol. We also found that substances such as catalase, glycerol and trehalose that may have protective roles under stressful conditions were accumulated in high amounts in the ethanol-tolerant mutant. The ethanol-tolerant mutant also exhibited resistance to other stresses including heat, high osmolarity and oxidative stress in addition to ethanol tolerance. These results indicate that the mutant exhibits multiple stress tolerance because of elevated expression of stress-responsive genes, resulting in accumulation of stress protective substances.

[Evaluation of acute hepatic failure treated at the Department of Medicine III, Kyushu University Hospital: indications for living-donor liver transplantation]

To evaluate indications for living-donor liver transplantation (LDLT), we examined 25 consecutive patients with acute hepatic failure admitted to the Department of Medicine III, Kyushu University Hospital between November 2001 and July 2004. These cases were diagnosed as fluminant hepatitis (n=13), severe-type acute hepatitis (n=11), or late-onset hepatic failure (n=1). Nine patients (36%) improved with conservative treatment (conservative treatment group), and the other 16 patients (64%) needed LDLT (LDLT indicated group). In the LDLT indicated group, 11 patients received LDLT, and 4 died because of lack of LDLT donors (n=3), or renal failure (n=1). The LDLT survival rate was 82% (9/11); two patients died due to hepatic infarction and brain edema, respectively. It is very important to predict whether a patient with acute hepatic failure belongs to the conservative treatment group or the LDLT indicated group on admission. Therefore, we analyzed variables that could influence prognosis, including, parameters of hepatic function and platelet counts on admission, and relative hepatic volume (%), which represents the ratio of hepatic volume measured by CT relative to standard hepatic volume calculated with body surface area. Univariate logistic analysis showed that relative hepatic volume, gammaglutamyl transpeptidase (gamma-GTP), alkaline phosphatase (ALP), and the ratio of direct bilirubin to total bilirubin (DB/TB) were significant predictors of survival (p < 0.05). Using these factors plus prothrombin time (PT) and total cholesterol, both of which were relatively significant predictors of survival (p < 0.2), we proposed a model for predicting the probability of survival by the stepwise method. Consequently, we proposed a model using four parameters: ALP, GGTP, PT, and relative hepatic volume (Volume) as shown below: p(%) = 1/(1+exp (-(-36.2375 + ALP x 0.0251 + gamma-GTP x 0.0102 + PT x 0.2558 + Volume 21.2158))) x 100. This model showed a significant correlation between prediction and consequence of survival (r2 = 0.7388, p = 0.0003). In conclusion, LDLT is an effective treatment for acute hepatic failure. The results of this study suggested that our model can adequately predict prognosis in the early phase of acute hepatic failure.

[Living donor liver transplantation for the patient with hepatocellular carcinoma]

Since 1989, over 3,000 living donor liver transplantation (LDLTx) were performed in Japan. Among them, LDLTx for advanced hepatocellular carcinoma (HCC) with severe liver cirrhosis have recently increased. LDLTx for HCC has been offered only when liver function was severely impaired, or HCC became uncontrollable by other modalities such as hepatic resection or ablation therapies, which often exceeded the Milan criteria. One-and 3-year survivals were 84.6% and 73.3%, respectively. When exceeding the Milan criteria, tumor size over 5 cm, vascular invasion, grade of histologic differentiation of HCC, and high PIVKA-II over 300 mAU/ml were independent risk factors for HCC recurrence. Prevention of HCC or hepatitis C recurrence after transplantation should be resolved to improve graft and patient survival.

Softening of Cu-O bond stretching phonons in tetragonal HgBa2CuO4+delta

Phonons in nearly optimally doped HgBa(2)CuO(4+delta) were studied by inelastic x-ray scattering. The dispersion of the low-energy modes is well described by a shell model, while the Cu-O bond stretching mode at high energy shows strong softening towards the zone boundary, which deviates strongly from the model. This seems to be common in the hole-doped high-T(c) superconducting cuprates, and, based on this work, not related to a lattice distortion specific to each material.

Kohn anomaly in MgB2 by inelastic X-ray scattering

We study phonons in MgB2 using inelastic x-ray scattering (1.6 and 6 meV resolution). We clearly observe the softening and broadening of the crucial E(2g) mode through the Kohn anomaly along GammaM, in excellent agreement with ab initio calculations. Low temperature measurements (just above and below T(c)) show negligible changes for the momentum transfers investigated and no change in the E(2g) mode at A between room temperature and 16 K. We report the presence of a longitudinal mode along GammaA near in energy to the E(2g) mode that is not predicted by theory.

Inhibition of matrix metalloproteinase-2 activity by siderophores of Pseudomonas species

To obtain a novel matrix metalloproteinase (MMP) inhibitor produced by bacteria, we have focused on the chelating activity of siderophores. Several siderophore-producing bacteria were isolated from soil using chrome azurol S agar plates and then the effect of siderophores on MMP-2 activity was assayed by gelatin zymography. The results showed that partially purified siderophores from ten isolated strains inhibited MMP-2 activity. Among these strains, two were non-fluorescent and eight were fluorescent Pseudomonas species. From these eight strains, pyoverdine-type siderophores were detected. The Zn(2+)-chelating activity of these siderophores correlated with the inhibition of MMP-2 activity. Therefore, it is considered that siderophores such as pyoverdines inhibit MMP-2 activity by chelating Zn(2+) on the active site of MMP-2.

Lack of evidence for a role of Epstein-Barr virus in the increase of lung cancer in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is known as an independent risk factor for lung cancer. Because Epstein-Barr virus (EBV) may be involved in the genesis of IPF as well as certain malignancies, we investigated whether EBV contributes to the increased incidence of lung cancer in IPF The formalin-fixed and paraffin-embedded lung sections were prepared from 22 lung cancer patients with IPF and 22 lung cancer patients without IPF All ofthe IPF patients pathologically showed usual interstitial pneumonia. In situ hybridization for EBV-encoded small non-polyadenylated RNAs failed to show positive signals in the cancer tissues of either IPF or non-IPF patients. This study did not provide evidence for an etiologic role of EBV in the development of lung cancer in IPF.

Isolation and characterization of a bacterium that degrades various polyester-based biodegradable plastics

Microorganisms isolated from soil samples were screened for their ability to degrade various biodegradable polyester-based plastics. The most active strain, designated as strain TB-13, was selected as the best strain for degrading these plastics. From its phenotypic and genetic characteristics, strain TB-13 was closely related to Paenibacillus amyloyticus. It could degrade poly(lactic acid), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(caprolactone) and poly(ethylene succinate) but not poly(hydroxybutylate-co-valerate). However, it could not utilize these plastics as sole carbon sources. Both protease and esterase activities, which may be involved in the degradation of plastic, were constitutively detected in the culture broth.

Electronic structure of MgB2 from angle-resolved photoemission spectroscopy

The first angle-resolved photoemission spectroscopy results from MgB2 single crystals are reported. Along the GammaK and GammaM directions, we observed three distinct dispersive features approaching the Fermi energy. These can be assigned to the theoretically predicted sigma (B 2p(x,y)) and pi (B 2p(z)) bands. In addition, a small parabolic-like band is detected around the Gamma point, which can be attributed to a surface-derived state. The overall agreement between our results and the band calculations suggests that the electronic structure of MgB2 is of a conventional nature, thus implying that electron correlations are weak and may be of little importance to superconductivity in this system.

Crucial Fas-Fas ligand interaction in spontaneous acceptance of hepatic allografts in mice

The Fas/Fas ligand (FasL) system plays important roles in the immune system, including host immunoregulation and cytotoxicity. In this study, we investigated the involvement of Fas-FasL interactions in spontaneous acceptance of hepatic allografts in murine orthotopic liver transplantation. Liver transplantation between the C57BL/6 (B6, H-2b) donor and the MRL/Mp (MRL, H-2k) recipient was performed in various combinations of donor and recipient mice with wild type (+/+), Fas-mutant (lpr) or FasL-mutant (gld) genotypes. The prolongation and spontaneous acceptance of the fully allogeneic grafts in recipients was not observed in either MRL-lpr recipients with B6+/+ livers or MRL+/+ recipients with B6-gld livers. Moreover, the serum alanine aminotransferase (ALT) levels and the degree of cell infiltration into hepatic allografts on day 7 after transplantation were inversely correlated with the recipient survival time (in days). The donor-specific cytotoxic T-lymphocyte (CTL) activities of the graft-infiltrating cells (GICs) from MRL-gld recipients with B6+/+ livers were much lower than those from MRL+/+ or -lpr recipients on days 5 and 10 after transplantation. However, the CTL activities of the GICs from MRL+/+ and -gld recipients predominantly disappeared by day 15 after transplantation. Furthermore, the anti-donor CTL activities induced in MRL+/+ recipients were ascribed to CD8+ cells, and were not mediated by Fas-FasL interactions. These results strongly suggest that the Fas/FasL system plays a critical role for recipient immunoregulation, enabling recipients in accepting hepatic allografts by deletion of the donor-specific T cells, but not for CTL/target cell interaction in MRL+/+ recipients.

Allogeneic hematopoietic stem cell transplantation for 27 children with juvenile myelomonocytic leukemia diagnosed based on the criteria of the International JMML Working Group

Prognostic factors of juvenile myelomonocytic leukemia (JMML) have not been clarified because of its very low incidence and inaccuracy in the diagnosis. The purpose of this study was to evaluate children with JMML given an allogeneic hematopoietic stem cell transplantation (SCT) and the role of different variables potentially influencing outcome in a nationwide survey in Japan based on the newly proposed criteria by the International JMML Working Group. The study patients were 27 children who underwent SCT among 55 JMML patients retrospectively collected in the survey. The source of grafts was HLA-identical siblings in 12 cases, HLA-matched unrelated individuals in 10 and others in five. Total body irradiation was used in 18 cases. Event-free and overall survival (OS) at 4 years after SCT were 54.2 +/- 11.2% (s.e.) and 57.9 +/- 11.0% (s.e.), respectively. Six patients died of relapse and three of complications. Patients with abnormal karyotypes showed a significantly lower OS than those with normal karyotypes (P < 0.001). Patients below 1 year of age showed a significantly higher OS than those of 1 year of age or more (P = 0.02). Patients with grade 0-1 acute graft-versus-host disease (GVHD) or chronic GVHD had a more favorable OS than those without them, although they were not statistically significant (P > 0.05). Other variables studied were not associated with OS. A multivariate analysis of these factors yielded the abnormal karyotype as the only significant risk factor for lower OS (risk ratio: 11.0; 95% CI: 2.7-45.1).

Bacterial distribution and phylogenetic diversity in the Changjiang estuary before the construction of the Three Gorges Dam

The bacterial community structure in the Changjiang estuary was studied for comparison with future changes, related to the construction of the Three Gorges Dam. Population densities of bacteria in the surface water at station C1 estimated by CFU on marine agar plates and by DAPI direct count, were 2.8 x 10(4) ml(-1) and 4.2 x 10(5) ml(-1), respectively. Physicochemical properties of water, such as temperature and salinity, suggested that station C1 was affected by freshwater from the Changjiang River. Cluster analysis of the PCR-RFLP patterns obtained from 9 samples showed that the bacterial community structure at station C1 was different from the structure at the other stations. Bacterial diversity in the surface water at station C1 was studied based on the genotypes of the 250 clones of 16S rRNA, and on the phenotypes generated on Biolog GN plates for 70 isolates. Sequences of bacteria from two common marine groups, alpha- and gamma-Proteobacteria, were frequently observed. Some other divisions, including the beta-Proteobacteria, C/F/B group, low G+C gram positive, high G+C gram positive, chloroplasts, and relatives of Verrucomicrobia were also observed. The putative dominant species based on both genotype and phenotype analyses were close relatives of Alteromonas macleodii or Roseobacter spp. These results reflected the nutrient-rich environment at station C1.

Hepatic artery reconstruction in living-donor liver transplantation: a review of its techniques and complications

BACKGROUND

Hepatic arterial reconstruction is one of the most difficult procedures in living-donor liver transplantation (LDLT) because the artery used is generally small in diameter and has a short stalk. If hepatic artery thrombosis (HAT) occurs, the recipient clinical course will be unstable. The introduction of microvascular hepatic arterial reconstruction has significantly decreased the incidence of HAT.

METHODS

Fifty-two cases of LDLT were performed from October 1995 to May 2001 in our institution. Hepatic arterial reconstruction was performed under microscopic guidance.

RESULTS

HATs were recognized in 2 cases (3.8%), both of which needed reoperation.

CONCLUSIONS

Surgeons who perform hepatic arterial reconstruction in LDLT should be highly trained in microvascular techniques to decrease the incidence of HAT. This commentary reviews the surgical techniques of hepatic arterial reconstruction and possible complications that may arise in a reconstructed hepatic artery.

Living-donor liver transplantation for fulminant hepatic failure in adult patients with a left-lobe graft

BACKGROUND

Living donors are practically the only source of organs in countries where the availability of cadaveric donors is severely restricted, such as Japan. A left-lobe graft, in which one third of the liver is donated, is therefore used for adult-to-adult living-donor liver transplantation (LDLT) in patients with fulminant hepatic failure (FHF).

METHODS

Fifteen adult patients with FHF, ranging from 22 to 59 years of age, were treated with LDLT with a left-lobe graft. Preoperative encephalopathy was grade II in 2 patients, grade III in 4 patients, and grade IV in 9 patients. The graft volume (GV) ranged from 260 to 570 mL, thus corresponding to 23% to 54% of the recipients' standard liver volume (SLV). The patients were divided into 2 groups according to their GV/SLV: a medium-size graft group (GV/SLV > or =30%; group M, n = 11) and a small-size graft group (GV/SLV <30%; group S, n = 4). The effects of GV/SLV on graft function and survival were compared. Postoperative neurologic complications were also evaluated.

RESULTS

The donors are all doing well. Twelve (80%) of the 15 recipients are still alive, with a follow-up period of from 3 to 43 months. No statistically significant differences were observed in the postoperative serum levels of bilirubin and alanine aminotransferase, prothrombin time, or frequency of postoperative complications between the 2 groups. The graft and patient survival rates were 75% (3/4) and 75% (3/4) in group S and 73% (8/11) and 82% (9/11) in group M, respectively. All patients who survived the perioperative period recovered without any neurologic sequelae.

CONCLUSIONS

The high success rate and low donor risk of LDLT may therefore justify its use for adult patients with FHF using a left-lobe graft.

Cloning and characterization of the T-box gene Tbx6 in Xenopus laevis

Tbx6 is a member of the T-box gene family. Studies of knockout mice indicate that Tbx6 is involved in somite differentiation. In the present study, we cloned Tbx6 from another vertebrate species, namely Xenopus laevis, and studied its roles in development. The expression of Tbx6 in Xenopus started from the early gastrula stage, reached a peak during the late gastrula to neurula stages and then declined. Initial expression of Tbx6 was observed in the paraxial mesoderm during the gastrula stage. The Tbx6-expressing region spread anteriorly and ventrally in the neurula stage. In the tailbud stage, the area of expression shrank caudally and was finally restricted to the tip of the tailbud. Overexpression of Tbx6 mRNA in dorsal blastomeres caused atrophy of the neural tube and inhibited differentiation of the notochord. Animal cap explants overexpressing Tbx6 or Tbx6VP16 mRNA, but not Tbx6EnR mRNA, differentiated mainly into ventral mesodermal tissues. This suggests that Tbx6 is a transcriptional activator. Higher doses of Tbx6 or Tbx6VP16 mRNA caused hardly any muscular differentiation. However, coinjection of Tbx6 mRNA with noggin mRNA elicited marked muscle differentiation. These results suggest that Tbx6 is implicated in ventral mesoderm specification but is involved in muscle differentiation when acting together with the dorsalizing factor noggin.

Clinical significance of potential pathogenic microorganisms of sputum in patients with pulmonary tuberculosis

BACKGROUND

Bacterial culture of sputum is frequently positive in patients with pulmonary tuberculosis (TB). However, it remains to be clarified whether detection of potential pathogenic microorganisms (PPM) in sputum represents bacterial infection or only colonization of the respiratory tract. In the present study, we investigated the clinical significance of PPM in patients with pulmonary TB.

METHODOLOGY

Sputum culture for PPM was studied in 174 pulmonary TB patients (117 males and 57 females, mean age of 71 years) on the day of admission. Ninety-seven patients (63 males and 34 females, mean age of 67.1 years) also underwent transtracheal aspirates (TTA). Quantitative culture of sputum and TTA was performed to distinguish infection from colonization. The results were evaluated as follows: more than 106 or 105 c.f.u./mL indicated infection in the case of sputum or TTA samples, respectively. We also compared various clinical parameters between patients with PPM and patients with non-potential pathogenic microorganisms (non-PPM).

RESULTS

Potential pathogenic microorganisms were positive in 44% and 24% of sputum and TTA specimens, respectively. However, quantitative culture for PPM showed positive findings in only 11% and 3% of sputum and TTA specimens, respectively. A comparative study of the clinical features revealed that PPM patients had a lower bodyweight and lower serum albumin levels than non-PPM patients. A fatal outcome was also more common in PPM patients than in non-PPM patients. Logistic regression analysis further confirmed that PPM clearly contributed to a fatal outcome in addition to the previously established parameters including age, performance status, haemoglobin, albumin and radiographic disease extent.

CONCLUSION

Although sputum PPM represent only colonization of the upper respiratory tract in TB patients, they are associated with a poor prognosis.

Biliary reconstruction in living donor liver transplantation with dye injection leakage test and without stent use

Biliary complication remains a significant source of morbidity and mortality in living donor liver transplantation. From October 1996 to December 1999, 34 patients underwent 35 living donor liver transplantations at Kyushu University Hospital. In the initial twenty cases, anastomotic internal stents were placed. In the most recent fifteen cases, no internal stent was inserted and routine postreconstruction dye injection leakage tests were administered. In recipient biliary reconstruction, hepaticojejunostomy was performed using interrupted sutures without an anastomotic stent. After an intestinal clamp was applied at the anal side of the hepaticojejunostomy, leakage test was done using diluted indigocarmine solution injected into the jejunal loop lumen. Two (13%) of the fifteen recent patients suffered from biliary complications, whereas eight patients (40%) from the former twenty patients suffered from biliary complications. We conclude that the use of the stent was not useful, but the application of the dye injection leakage test was useful.

Succession of microbial communities during a biostimulation process as evaluated by DGGE and clone library analyses

AIMS

The objective of this study was to investigate the changes in the indigenous bacterial community structure for assessing the impact of biostimulation on spilled oil.

METHODS AND RESULTS

Changes in the bacterial community structure were monitored by denaturing gradient gel electrophoresis (DGGE) and clone library methods based on 16S rRNA gene (rDNA) sequences. The results of DGGE, coupled with the use of the Shannon index and principal component analysis (PCA) and clone library analyses, were consistent. In the treated (fertilized) area, one operational taxonomic unit (OTU) became dominant during the fertilization period, and it was most closely related to Pseudomonas putida.

CONCLUSIONS

The bacterial community structure in the treated area was markedly different from that in the control (non-fertilized) area during the fertilization period, but in the two areas it became similar at 14 weeks after the end of fertilization.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results suggest that the bacterial community structure was disrupted by the biostimulation treatment, but that it recovered immediately after the end of fertilization.

Preferential binding of polyethylene glycol-coated liposomes containing a novel cationic lipid, TRX-20, to human subendthelial cells via chondroitin sulfate

PURPOSE

To design novel cationic liposomes, polyethylene glycol (PEG)-coated cationic liposomes containing a newly synthesized cationic lipid, 3,5-dipentadecyloxybenzamidine hydrochloride (TRX-20) were formulated and their cellular binding and uptake investigated in vitro in the following cells: human subendothelial cells (aortic smooth muscle cells and mesangial cells) and human endothelial cells.

METHODS

Three different PEG-coated cationic liposomes were prepared by the extrusion method, and their mean particle size and zeta potential were determined. Rhodamine-labeled PEG-coated cationic liposomes were incubated with smooth muscle cells, mesangial cells, and endothelial cells at 37 degrees C for 24 h. The amounts of cellular binding and uptake of liposomes were estimated by measuring the cell-associated fluorescence intensity of rhodamine. To investigate the binding property of the liposomes, the changes of the binding to the cells pretreated by various kinds of glycosaminoglycan lyases were examined. Fluorescence microscopy-is used to seek localization of liposomes in the cells.

RESULTS

The cellular binding and uptake of PEG-coated cationic liposomes to smooth muscle cells was depended strongly on the chemical species of cationic lipids in these liposomes. Smooth muscle cells bound higher amount of PEG-coated TRX-20 liposomes than other cationic liposomes containing N-(1-(2.3-dioleoyloxy) propyl)-N, N, N-trimethylammonium salts or N-(alpha-(trimethylammonio)acetyl)-D-glutamate chloride. Despite of the higher affinity of PEG-coated TRX-20 liposomes for subendothelial cells, their binding to endothelial cells was very small. The binding to subendothelial cells was inhibited when cells were pretreated by certain kinds of chondroitinase, but not by heparitinase. These results suggest that PEG-coated TRX-20 liposomes have strong and selective binding property to subendothelial cells by interacting with certain kinds of chondroitin sulfate proteoglycans (not with heparan sulfate proteoglycans) on the cell surface and in the extracellular matrix of the cells. This binding feature was different from that reported for other cationic liposomes.

CONCLUSIONS

PEG-coated TRX-20 liposomes can strongly and selectively bind to subendothelial cells via certain kinds of chondroitin sulfate proteoglycans and would have an advantage to use as a specific drug delivery system.

Effects of alpha-D-glucosylglycerol on the in vitro digestion of disaccharides by rat intestinal enzymes

Alpha-D-glucosylglycerol (GG) is a mixture of 2-O-alpha-D-glucosylglycerol (GG-II), (2R)-1-O-alpha-D-glucosylglycerol (R-GG-I) and (2S)-1-O-alpha-D-glucosylglycerol (S-GG-I). GG has been found to be slightly hydrolyzed in vitro only by rat intestinal enzymes, but hardly at all by other digestive juices. GG suppressed the hydrolysis of maltose, sucrose and isomaltose by rat intestinal enzymes because the amount of glucose in the digestion of a mixture of GG and disaccharide was less than the sum of that in each individual digestion. The consumption of GG was suppressed by isomaltose, but promoted by maltose, with the hydrolysis of GG being suppressed. Sucrose appeared to suppress only the consumption of S-GG-I, suggesting that S-GG-I was hydrolyzed by the active site of sucrase in a sucrase-isomaltase complex. Transglucosylation seems to have occurred more frequently in the individual digestion of maltose and isomaltose than in that of GG and sucrose. GG seemed to promote transglucosylation in the presence of maltose, to suppress it with sucrose, and to delay it with isomaltose.

ON-OFF retinal ganglion cells temporally encode OFF/ON sequence

While the functions of ON and OFF retinal ganglion cells have been intensively investigated, that of ON-OFF cells has not. In the present study, the temporal properties of spike trains emitted from ON-OFF cells in response to randomly flickering or multiphase ramp stimuli were examined in the Japanese quail. The results indicate that the firing of ON-spikes was influenced by the recent firing of OFF-spikes, and vice versa. As a result of this interaction, OFF/ON sequence of light intensity change was encoded with a spike pair with an interval of 20 ms, indicating that temporal coding is utilized in the vertebrate visual system as early as the retina. Thus, the present results suggest that retinal neuronal circuits may detect specific sequential features of stimuli.

Protective cytotoxic T lymphocyte responses induced by DNA immunization against immunodominant and subdominant epitopes of Listeria monocytogenes are noncompetitive

Taking advantage of the fact that plasmid DNA encoding a single cytotoxic T lymphocyte (CTL) epitope can induce CTLs, we examined the influence of T-cell responses to dominant epitopes on those to a subdominant epitope derived from Listeria monocytogenes. Our data suggest that interaction between T cells against dominant and subdominant epitopes does not operate in the generation of the hierarchy. Furthermore, we found that a single dominant epitope is sufficient for the induction of protective immunity.

Small graft for living donor liver transplantation

OBJECTIVE

To evaluate the impact of graft size on recipients in living donor liver transplantation (LDLT) to establish a clinical guideline for the minimum requirement.

SUMMARY BACKGROUND DATA

Although the minimum graft size required for LDLT has been reported to be 30% to 40% of graft volume (GV)/standard liver volume (SLV), the safety limit of the graft size was unknown.

METHODS

A total of 33 cases of LDLT, excluding auxiliary transplantation, were reviewed with a minimum observation period of 4 months. The 33 patients were divided into three groups according to GV/SLV: medium-size graft group, small-size graft group, and extra-small graft group. The effect of GV/SLV on graft function, graft regeneration, and survival was evaluated.

RESULTS

The overall patient survival rate was 94% at a mean follow-up of 15 months with a minimum observation period of 4 months. There were no statistically significant differences in postoperative bilirubin clearance, alanine aminotransferase, prothrombin time, and frequency of postoperative complications among the three groups. One week after transplantation, the regeneration rate (GV at 1 week/harvested GV) in the extra-small and small groups was significantly higher than that of the medium group. The graft and patient survival rates were both 100% in the extra-small group, 75% and 88% in the small group, and 90% and 95% in the medium group.

CONCLUSIONS

Small-for-size grafts less than 30% of SLV can be used with careful intraoperative and postoperative management until the grafts regenerate.