Incidence and risk factors of renal dysfunction after liver transplantation in Korea

Renal dysfunction, one of the most common complications after liver transplantation, influences patient outcomes. Little is known, however, about it in Korea. The aims of this study were to determine the incidence and to identify the risk factors for renal dysfunction after liver transplantation. Sixty-two patients who survived over 6 months after transplantation were enrolled. Renal function was classified by creatinine clearance (Ccr, mL/min), which was estimated using the Cockcroft-Gault formula. Twenty-seven patients (44%) showed mild renal dysfunction (60 < or = Ccr < 90), and 27 patients (44%), moderate dysfunction (30 < or = Ccr < 60). The others were found to have normal function (Ccr > or = 90). None displayed severe dysfunction (Ccr < 30). Compared to a control group (Ccr > or = 60), the renal dysfunction group showed lower preoperative Ccr (91 +/- 28.6, 63 +/- 21.9, respectively, P < .01) and lower Ccr at 3 months after transplantation (72 +/- 17.1, 49 +/- 14.6, respectively, P < .05). Age, sex, immunosuppressive drug usage, serum tacrolimus levels, and the frequency of postoperative acute renal failure did not affect the postoperative renal dysfunction. Twenty-six patients received mycophenolate mofetil while reducing the dose of calcineurin inhibitors because of compromised renal function. With mycophenolate mofetil treatment, the renal function seemed to improve, although the difference was not statistically significant (P = .057). These data demonstrate that renal dysfunction is common after liver transplantation and that preoperative renal function is the important factor predicting postoperative renal dysfunction.

Intraoperative assessment of hepatic venous congestion with direct clamping of the hepatic vein trunk for living donor liver transplantation

We devised a hepatic vein clamping method to assess the amount of hepatic venous congestion (HVC) before liver transection. From February 2003 to May 2003, this method was applied to 5 of 58 living donor livers especially to assess donor safety. The left portal vein and proper hepatic artery as well as the middle hepatic vein (MHV)-left hepatic vein (LHV) trunk were clamped simultaneously to assess the HVC in the remnant right lobe before performing extended left lobectomy. As three donors demonstrated the extent of the HVC equivalent to about 40% of the right lobe volume (RLV), their operations proceeded according to the preoperative plan. The territory of HVC after liver transection was the same as that observed with direct clamping of the hepatic vein. However, one donor showed massive HVC more than 50% of RLV and the operative plan was adjusted to harvest only the left lobe without the MHV trunk for donor safety. To assess the HVC in the remnant left lobe, the isolated LHV trunk was occluded after clamping the donor's proper hepatic artery. The whole left lobe except for a small area at the anterior portion of the medial segment became discolored on LHV clamping: the opposite demarcation appeared on MHV clamping. The amount of HVC was so small that we harvested the right lobe with the MHV trunk. All donors and recipients recovered uneventfully. We believe that this direct clamping method makes the assessment of HVC feasible before parenchymal transection of a donor liver.

On the structural and functional modularity of glycinamide ribonucleotide formyltransferases

Glycinamide ribonucleotide formyltransferases (GARTs) are part of the de novo purine biosynthetic pathway, catalyzing the direct transfer of a formyl group from the tetrahydrofolate cofactor to the glycinamide ribonucleotide substrate. Despite the low amino acid-sequence identity between the GARTs from Escherichia coli and human, their tertiary structures are superimposable. As part of our functional studies of these enzymes, we have investigated the interchangeability of individual protein fragments or modules between the two enzymes and the functional properties of the resulting hybrids. The modular nature of GART facilitated the creation of combinatorial libraries of chimeras between the Escherichia coli and human enzymes, which were functionally selected through complementation of an auxotrophic Escherichia coli strain. From a pool of several dozen sequence distinct hybrids, six in vivo-functional fusion genes were selected, overexpressed, and purified to homogeneity. The kinetic analysis of these constructs and the comparison of their k(cat) and K(M) values to the parental enzymes suggest that the characteristic kinetic properties from the two parents are "modular encoded" and can be exchanged by domain swapping. The chimeras in general, however, are subject to temperature instability and misfolding; thus, they serve primarily as useful candidates for further rounds of optimization.

A comparison of responses from olfactory receptor neurons of Heliothis subflexa and Heliothis virescens to components of their sex pheromone

Single-cell electrophysiological recordings were obtained from olfactory receptor neurons in sensilla trichodea on male antennae of the heliothine species Heliothis subflexa and the closely related congener H. virescens. A large percentage of sensilla (72% and 81%, respectively, of all sensilla sampled) contained a single odor-responsive receptor neuron tuned to the major pheromone component of both species, Z-11-hexadecenal. A second population of sensilla on H. subflexa antennae (18%) housed receptor neurons that were tuned to Z-9-hexadecenal but also responded with less sensitivity to Z-9-tetradecenal. A similar population of sensilla (4%) on H. virescens male antennae housed receptor neurons that were shown to be tuned specifically only to Z-9-tetradecenal, with no response to even high dosages of Z-9-hexadecenal. A third population of sensilla (comprising 8% and 16% of the sensilla sampled in H. subflexa and H. virescens, respectively) housed two olfactory receptor neurons, one of which was tuned to Z-11-hexadecenyl acetate and the other tuned to Z-11-hexadecenol. In H. subflexa the Z-11-hexadecenyl acetate-tuned neuron also responded to Z-9-tetradecenal with nearly equivalent sensitivity. The behavioral requirements of males of these two species for distinct pheromonal blends was, therefore, reflected by the subtle differences in the tuning properties of antennal olfactory receptor neurons.

Elastic stiffness of the nuclear-spin system in tetragonal U2D2 nuclear-ordered solid (3)He

We have measured temperature dependences of sound velocity for both longitudinal and transverse sound in nuclear-ordered U2D2 solid 3He with several crystal orientations along the melting curve. The sound velocity change was proportional to T4 for all sound modes and crystal orientations and was attributed to the nuclear-spin part of the internal energy. We extracted six-independent elastic stiffness of the nuclear-spin part and obtained Grüneisen constants of the spin wave velocity for four-independent strains. Grüneisen constants for compressional strain were larger than those for shear strain. Using the multiple-spin-exchange model, we explain the anisotropy of Grüneisen constants in tetragonal symmetry.

Deep venous thrombosis associated with protein C and/or S deficiency: management with catheter-directed thrombolysis

We performed this study to evaluate the efficacy of catheter-directed thrombolysis with urokinase in treating acute symptomatic iliofemoral deep venous thrombosis associated with protein C and/or S deficiency. A total of 42 consecutive patients with deep venous thrombosis were seen between September 2000 and August 2002. Of these, catheter-directed thrombolysis via the popliteal vein was performed in 5 patients (11.9%) with acute iliofemoral deep venous thrombosis associated with protein C and/or S deficiency. Average duration of symptoms was 4.2 days (range, 1-7 days). The average urokinase dose was 2.7 million IU (range, 0.6 million to 7.0 million IU) infused over an average of 33.1 h (range, 16-67 h). Lysis was complete in all five treated cases. Two cases had underlying iliac venous stenoses (>50%) that were treated with angioplasty and stent placement. In one patient in whom recanalization of a right iliac vein occlusion was successful, thrombosis occurred in the treated vein within 3 weeks of intervention despite full anticoagulation therapy, and further intervention was required. There were no complications or clinically detectable pulmonary emboli. The technical and clinical success rates were 100%. This initial experience suggests that catheter-directed thrombolysis for treatment of acute symptomatic iliofemoral deep venous thrombosis associated with protein C and/or S deficiency is safe and effective.

Characterization of a thermostable D-stereospecific alanine amidase from Brevibacillus borstelensis BCS-1

A gene encoding a new thermostable D-stereospecific alanine amidase from the thermophile Brevibacillus borstelensis BCS-1 was cloned and sequenced. The molecular mass of the purified enzyme was estimated to be 199 kDa after gel filtration chromatography and about 30 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the enzyme could be composed of a hexamer with identical subunits. The purified enzyme exhibited strong amidase activity towards D-amino acid-containing aromatic, aliphatic, and branched amino acid amides yet exhibited no enzyme activity towards L-amino acid amides, D-amino acid-containing peptides, and NH(2)-terminally protected amino acid amides. The optimum temperature and pH for the enzyme activity were 85 degrees C and 9.0, respectively. The enzyme remained stable within a broad pH range from 7.0 to 10.0. The enzyme was inhibited by dithiothreitol, 2-mercaptoethanol, and EDTA yet was strongly activated by Co(2+) and Mn(2+). The k(cat)/K(m) for D-alaninamide was measured as 544.4 +/- 5.5 mM(-1) min(-1) at 50 degrees C with 1 mM Co(2+).

Effect of dissolved oxygen concentration on the biofilm and in situ analysis by fluorescence in situ hybridization (FISH) and microelectrodes

A better understanding of microbiology and ecology of nitrifying bacteria in inner biofilms is an important part of improving process performance and control. Microelectrodes and fluorescent in situ hybridization (FISH) in biofilm research have been used to investigate the spatial distributions of various microbial activities in biofilms and have led to new experimental findings as well as modifications of the homogeneous assumptions in the biofilm kinetic models. The objective of this study is to try the combination of two methods, both FISH and microelectrode measurements, and to provide reliable and in situ information on nitrifying bacterial activity in biofilms. The characteristics of biofilm developed on tygon slides were different according to the change of dissolved oxygen (DO). When the DO increased from 2 to 10 mg DO/L, the rate of the biofilm thickness increased and its dry density changed from 50-70 to 25-90 mg/cm3. Ammonia oxidizing bacteria were not uniformly distributed in biofilm, and were found at the deeper layer where oxygen is depleted, they were detected primarily in the upper and middle layers of the biofilm.

Geobacillus toebii sp. nov., a novel thermophilic bacterium isolated from hay compost

A thermophilic, spore-forming rod isolated from hay compost in Korea was subjected to a taxonomic study. The micro-organism, designated strain SK-1(T), was identified as being aerobic, Gram-positive, motile and rod-shaped. Growth of the isolate was observed at 45-70 degrees C (optimum 60 degrees C) and pH 6.0-9.0 (optimum pH 7.5). The G+C content of the genomic DNA was 43.9 mol%. Chemotaxonomic characteristics of the isolate included the presence of mesodiaminopimelic acid in the cell wall and iso-C15:0 and iso-C17:0 as the major cellular fatty acids. The predominant isoprenoid quinone was MK-7. The chemotaxonomic characteristics of strain SK-1(T) were the same as those of the genus Geobacillus. Phylogenetic analysis based on 16S rDNA sequences showed that strain SK-1(T) is most closely related to Geobacillus thermoglucosidasius. However, the phenotypic properties of strain SK-1(T) were clearly different from those of G. thermoglucosidasius. The level of DNA-DNA relatedness between strain SK-1(T) and the type strain of G. thermoglucosidasius was 27%. On the basis of the phenotypic traits and molecular systematic data, strain SK-1(T) represents a novel species within the genus Geobacillus, for which the name Geobacillus toebii sp. nov. is proposed. The type strain is strain SK-1(T) (= KCTC 0306BP(T) - DSM 14590(T)).

Adult-to-adult living donor liver transplantation at the Asan Medical Center, Korea

Between February 1997 and December 2001, 311 adult-to-adult living donor liver transplants (A-A LDLTs) were performed at the Asan Medical Center for patients above 20 years of age. Indications for A-A LDLT were: chronic hepatitis B (203), chronic hepatitis C (5), hepatocellular carcinoma (64), alcoholic cirrhosis (9), cryptogenic cirrhosis (4), secondary biliary cirrhosis (5), primary biliary cirrhosis (1), Wilson' s disease (2), autoimmune hepatitis (1), hepatic tuberculosis (1), cholangiocarcinoma (1), fulminant hepatic failure (14) and primary non-function of cadaveric liver graft (1). Of 311 A-A LDLTs, 36 were of medical high urgency, 20 were for acute and subacute hepatic failure, 15 were for hepato-renal syndrome and 1 was for primary non-function. Recipient age ranged from 27 to 64 years. Donor age ranged from 16 to 62 years. There was no donor mortality. Implanted liver grafts were categorized into seven types: 175 modified right lobe (MRL), 70 left lobe, 32 right lobe, 20 dual grafts, 10 left lobe plus caudate lobe, three extended right lobe and one posterior segment. In MRL, the tributaries of the middle hepatic vein were reconstructed by interpositioning a vein graft. Indication for dual graft implantation was the same as single graft A-A LDLT, and four of 20 were emergency cases. Of 20 dual grafts, 14 received two left lobes, four received a left lobe and a lateral segment, one received a right lobe and a left lobe and one received a lateral segment and a posterior segment. Graft volume ranged from 28% to 83% of the standard liver volume of the recipients. There were 33 (10.6%) in-hospital mortalities (< 4 months) among the 310 patients after 311 A-A LDLTs. Of the 36 patients receiving emergency transplants, 31 survived. These encouraging results justify the expansion of A-A LDLT in coping with increasing demands, even in urgent situations. We have aimed to introduce the establishment of the efficacy of A-A LDLT in various end-stage chronic and acute liver diseases, as well as new technical advances to overcome small graft-size syndrome by using dual-graft implantation and MRL, both of which were first developed in our department.

Peripheral arterial insufficiency associated with protein C deficiency

Two patients with protein C deficiency who presented with peripheral arterial insufficiency were successfully managed. One patient was managed with bypass surgery for focal gangrene followed by full anticoagulation whilst the other patient was managed with full anticoagulation. Both patients showed characteristic arteriographic findings. Patients who present with peripheral arterial insufficiency demonstrating thrombotic occlusion of main peripheral artery without atherosclerosis and other risk factors should be evaluated for hypercoagulable states.

Interdependent effect of angiotensin-converting enzyme and platelet-activating factor acetylhydrolase gene polymorphisms on the progression of immunoglobulin A nephropathy

In order to investigate the interdependent action of the insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene and polymorphism in exon 11 (C1136-->T; Ala379Val) of the platelet-activating factor acetylhydrolase (PAF-AH) gene, which encodes a functional antagonist of PAF, on the progression of immunoglobulin A (IgA) nephropathy, we analysed both polymorphisms in patients with primary IgA nephropathy, who were followed-up for longer than 3 years. During the follow-up (87.3 +/- 50.0 months), the disease progressed in 38 of the 191 patients (19.9%). The D allele of the ACE gene in the absence of the T allele of the PAF-AH gene did not affect the prognosis [odds ratio (OR), 3.6; 95% confidence interval (CI), 0.8-16.4] and neither did the T allele in the absence of the D allele (OR, 3.0; 95% CI, 0.4-24.2). However, the presence of both was a significant prognostic factor (OR, 6.6; 95% CI, 1.4-31.3). After adjusting for other risk factors, the presence of both proved to be an independent risk factor (OR, 4.5; 95% CI, 1.6-12.7). These results suggest that the interdependent effects of ACE and PAF-AH polymorphisms on the progression of IgA nephropathy might be more important than the effect of the individual polymorphisms.

Health development experience in North and South Korea

The purpose of this study is to compare the difference in health status between South Koreans and North Koreans and to identify factors responsible for the remarkable improvements in the health status of South Koreans. In order to examine the causes of the difference in health level, the health indices and their determinants of two Koreas were analyzed in time order. As of the year 2000, the average life expectancy at birth is 71.0 years for men and 78.6 years for women in South Korea, which is longer than that of North Korea by 8.1 for men and 11.2 for women. Infant mortality rate in 1998 was 9.0 per 1,000 live births in South Korea and 54.0 in North Korea. Since being liberated from Japanese ruling in 1945, South Korea has achieved remarkable economic growth under democracy and a market economy system. On the other hand, North Korea has maintained a socialistic system. North Korea has suffered from economic crisis since the 1990s. From this point it could be said that economic status is the major factor for the differences in health level between the two Koreas. Economic status not only directly influences health level but also indirectly affects it through influences on nutrition, hygiene, health resources, and other intervening factors. The South Korean government has concentrated its limited resources on public health activities such as tuberculosis control, family planning (FP), and maternal and child health (MCH) programmes whereas the private sector has taken charge of constructing the health delivery system including health facilities and human resources. In order to solve the problem, which might occur in the private-oriented medical care system, the South Korean government has introduced the national health insurance programme and enforced regulation policies. Many developing countries which are suffering from poverty and disease, can learn from the experience of Korea that had suffered from similar problems up to the early 1970s.

Host cell proteins binding to the encapsidation signal epsilon in hepatitis B virus RNA

The highly conserved encapsidation signal (epsilon) of hepatitis B viral (HBV) pregenomic RNA has been reported as an essential component for encapsidation and protein priming of HBV polymerase. Here, we report that two HBV epsilon RNA-binding host proteins (80 and 43 kDa) and a copurifying protein (100 kDa) were purified and characterized by the combined methods of UV cross-linking analysis with the epsilon RNA and column chromatography. Amino-terminal microsequencing showed that 80- and 43-kDa proteins were identified as the heterodimeric nuclear factor of activated T cells (NF90/NF45) and 100 kDa as a molecular chaperone, the GRP94. The heterodimeric factor interacted preferentially with the upper-bulge region of HBV epsilon RNA helping the HBV polymerase bind the lower-bulge region. Using in vitro protein priming analysis, the initial oligonucleotide of the protein-priming product was deduced as 5'-GAAC-3', which is the complementary sequence of both regions of DR1 and epsilon in the pregenomic RNA. Previously, we also proposed that the GRP94 was associated with HBV polymerase in the human liver cell HepG2. These results suggest that the heterodimeric factor plays an important role in the priming activity of HBV polymerase.

Characterization of Symbiobacterium toebii, an obligate commensal thermophile isolated from compost

A symbiotic thermophilic bacterium, strain SC-1, was isolated from hay compost (toebi) in Korea. The new isolate exhibited an obligate commensal interaction with a thermophilic Geobacillus strain and required crude extracts and/or culture supernatant from Geobacillus sp. SK-1 for axenic growth. The growth factors from Geobacillus sp. SK-1 were irreversibly inactivated by phenol or protease treatment, suggesting that they might be proteins. The cells of strain SC-1 were non-spore forming, nonmotile rods that were stained Gram-negatively. The isolate was a microaerophilic heterotroph. Growth was observed between 45 degrees and 70 degrees C (optimum: 60 degrees C; 2.4-h doubling time) and pH 6.0 and 9.0 (optimum: pH 7.5). The G+C content of the genomic DNA was 65 mol%, and the major quinones were MK-6 and MK-7. A phylogenetic analysis of its 16S rDNA sequence indicated that strain SC-1 is closely related to Symbiobacterium thermophilum and so was named Symbiobacterium toebii on the basis of its physiological and molecular properties.

Catalytic asymmetric synthesis of cyclopentenones from propargyl malonates and allylic acetate by successive action of homogeneous palladium(II) and cobalt on charcoal catalysts in a one-pot reaction

The tandem action of a homogeneous chiral Pd(II) catalyst and a heterogeneous Co/C catalyst leads to a two-step one-pot highly enantioselective Pauson-Khand-type reaction.

Transcriptional repression of the human p53 gene by cobalt chloride mimicking hypoxia

The switch to an angiogenic phenotype is known to be a fundamental determinant of neoplastic growth and tumor progression. We herein report that the transcription of the human p53 gene was repressed by treatment with a hypoxia-mimicking concentration of cobalt chloride and alone by hypoxia-inducible factor 1alpha. Analyses of serial deletions, site-directed mutageneses and heterologous promoter systems showed that the site responsible for the repression by both factors was the E-box element in the promoter of the p53 gene. These results alongside previous data suggest that the loss of p53 including the transcriptional repression may play an important role in the angiogenic switch during tumorigenesis.

Anti-tumor effect associated with down-regulation of MHC class 1 antigen after co-transfection of GM-CSF and IFN-gamma genes in CT26 tumor cells

We previously reported that co-expression of GM-CSF and IFN-gamma genes in tumors induces a synergistic anti-tumor effect. Interestingly, we have used flow cytometry to identify two kinds of populations of CT26 cells that co-express GM-CSF and IFN-gamma genes: one population (CT26/G/I-down) that expresses very low levels of MHC class I and a second population (CT26/G/I-up) that expresses high levels of H-2Kd antigen. We have compared the anti-tumor effect between CT26/I-up and CT26/G/I-down cells. When wild-type (wt) CT26 cells were injected subcutaneously into Balb/c mice, tumor was formed 5-7 days after injection. However, when both CT26/G/I-up and CT26/G/I-down cells were injected, we did not identify any tumor. The protection' study showed that both CT26/G/I-up and CT26/G/I-down. cells could induce systemic immunity against secondary challenge with unmodified parental tumor cell. CT26/G/I-down cells showed normal expression of the heavy chain of MHC class I (HC), beta2-microglobulin (beta2m) and the TAP gene. Furthermore, in CT26/G/I-down cell, although the MHC molecules were detected normally in the cytoplasmic fraction, no message was detected in the membrane fraction. Pulse-chase experiments showed that class I antigen was normally synthesized like wt CT26 or CT26/G/I-up cells. Based on our results, non-MHC restricted immune effectors might play the major role in synergistic anti-tumor effects with co-expression of GM-CSF and IFN-gamma in CT26 tumor model.

Close correlation of p53 mutation to microvascular invasion in hepatocellular carcinoma

Mutation of p53 is a poor prognostic indicator of hepatocellular carcinoma (HCC). Although poor histologic differentiation of HCC has been associated with p53 mutations, the exact reasons for unfavorable clinical outcomes in patients with HCC remain to be clarified. In this study, we evaluate the association between p53 mutation and histopathologic features of HCCs, as well as tumor recurrences and survival. We examined 20 HCCs and surrounding liver tissues from patients who underwent surgical resection, and we performed direct sequencing of p53 gene. p53 mutations were found in 9 of 20 HCCs; none were found in the surrounding liver tissue. p53 mutations were frequent in large, multinodular, and poorly differentiated HCCs. Five of 9 with p53 mutation (in contrast, none of 11 with wild-type mutation) showed microvascular invasions. Hepatocellular carcinoma recurred in 6 of 9 with p53 mutation, in contrast to only 2 of 11 with wild-type mutation. The 1-year survival rate with p53 mutation was significantly lower than that with wild-type. In conclusion, it is suggested that p53 mutations tend to be commonly associated with microvascular invasions, which may result in micrometastasis, followed by frequent recurrences.