Multi-organ, multi-lineage engraftment by a single bone marrow-derived stem cell

Purification of rare hematopoietic stem cell(s) (HSC) to homogeneity is required to study their self-renewal, differentiation, phenotype, and homing. Long-term repopulation (LTR) of irradiated hosts and serial transplantation to secondary hosts represent the gold standard for demonstrating self-renewal and differentiation, the defining properties of HSC. We show that rare cells that home to bone marrow can LTR primary and secondary recipients. During the homing, CD34 and SCA-1 expression increases uniquely on cells that home to marrow. These adult bone marrow cells have tremendous differentiative capacity as they can also differentiate into epithelial cells of the liver, lung, GI tract, and skin. This finding may contribute to clinical treatment of genetic disease or tissue repair.

Circulating adhesion molecules VCAM-1, ICAM-1, and E-selectin in carotid atherosclerosis and incident coronary heart disease cases: the Atherosclerosis Risk In Communities (ARIC) study

BACKGROUND

Recruitment of circulating leukocytes at sites of atherosclerosis is mediated through a family of adhesion molecules. The function of circulating forms of these adhesion molecules remains unknown, but their levels may serve as molecular markers of subclinical coronary heart disease (CHD).

METHODS AND RESULTS

To determine the ability of circulating vascular cell adhesion molecule-1 (VCAM-1), endothelial-leukocyte adhesion molecule-1 (E-selectin), and intercellular adhesion molecule-1 (ICAM-1) to serve as molecular markers of atherosclerosis and predictors of incident CHD, we studied 204 patients with incident CHD, 272 patients with carotid artery atherosclerosis (CAA), and 316 control subjects from the large, biracial Atherosclerosis Risk In Communities (ARIC) study. Levels of VCAM-1 were not significantly different among the patients with incident CHD, those with CAA, and control subjects. Higher levels of E-selectin and ICAM-1 were observed for the patients with CHD (means [ng/mL]: E-selectin, 38.4; ICAM-1, 288.7) and those with CAA (E-selectin, 41.5; ICAM-1, 283.6) compared with the control subjects (E-selectin, 32.8; ICAM-1, 244.2), but the distributions were not notably different between the patients with CHD and CAA. Results of logistic regression analyses indicated that the relationship of ICAM-1 and E-selectin with CHD and CAA was independent of other known CHD risk factors and was most pronounced in the highest quartile. The odds of CHD and CAA were 5.53 (95% CI, 2.51-12.21) and 2.64 (95% CI, 1.40-5.01), respectively, for those with levels of ICAM-1 in the highest quartile compared with those in the lowest quartile. Odds of CAA were 2.03 (95% CI, 1.14-3.62) for those with levels of E-selectin in the highest quartile compared with those in the lowest quartile.

CONCLUSIONS

These data indicate that plasma levels of ICAM-1 and E-selectin may serve as molecular markers for atherosclerosis and the development of CHD.

Preparation and characterization of chitosan microparticles intended for controlled drug delivery

Chitosan microparticles were prepared with tripolyphosphate (TPP) by ionic crosslinking. The particle sizes of TPP-chitosan microparticles were in range from 500 to 710 microm and encapsulation efficiencies of drug were more than 90%. The morphologies of TPP-chitosan microparticles were examined with scanning electron microscopy. As pH of TPP solution decreased and molecular weight (MW) of chitosan increased, microparticles had more spherical shape and smooth surface. Release behaviors of felodipine as a model drug were affected by various preparation processes. Chitosan microparticles prepared with lower pH or higher concentration of TPP solution resulted in slower felodipine release from microparticles. With decreasing MW and concentration of chitosan solution, release behavior was increased. The release of drug from TPP-chitosan microparticles decreased when cross-linking time increased. These results indicate that TPP-chitosan microparticles may become a potential delivery system to control the release of drug.

New class of polymers for the delivery of macromolecular therapeutics

Cationic polymers show promise for the in vitro and in vivo delivery of macromolecular therapeutics. Known cationic polymers, e.g., poly(L)lysine (PLL) and polyethylenimine (PEI), have been employed in native and modified forms for the delivery of plasmid DNA (pDNA) and reveal varying levels of toxicity. Here, we report the preparation of a new class of cationic polymers that are specifically designed to deliver macromolecular therapeutics. Linear, cationic, beta-cyclodextrin (beta-CD)-containing polymers (CD-polymers) are synthesized by copolymerizing difunctionalized beta-CD monomers (AA) with other difunctionalized comonomers (BB) such that an AABBAABB product is formed. The beta-CD polymers are able to bind approximately 5 kbp pDNA above polymer to DNA (+/-) charge ratios of 1.5, compact the bound pDNA into particles of approximately 100-150 nm in size at charge ratios above 5+/-, and transfect cultured cells at charge ratios above 10+/-. In vitro transfections with the new beta-CD-polymers are comparable to the best results obtained in our hands with PEI and Lipofectamine. Some cell line-dependent toxicities are observed for serum-free transfections; however, no toxicity is revealed at charge ratios as high as 70+/- in transfections conducted in 10% serum. Single IV and IP doses as high as 200 mg/kg in mice showed no mortalities.

Congestion of right liver graft in living donor liver transplantation

BACKGROUND

Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. One solution to this problem is to use a right liver graft without a middle hepatic vein (MHV). However, the need for drainage from the MHV tributaries has not yet been described.

METHODS

Five right liver grafts without a MHV were transplanted in patients including two hepatitis B virus-cirrhosis, two fulminant hepatic failure and one secondary biliary cirrhosis. The graft weight ranged from 650 to 1,000 g, corresponding to 48 to 83% of the standard liver volume of the recipients.

RESULTS

Two of five recipients were complicated with severe congestion of the right median sector immediately after reperfusion, followed by prolonged massive ascites and severe liver dysfunction. One of the patients died of sepsis with progressive hepatic dysfunction 20 days after the operation.

CONCLUSIONS

Preservation and reconstruction of the MHV tributaries is recommended to prevent congestion of the right liver graft without MHV.

Liver transplantation for "very early" intrahepatic cholangiocarcinoma: International retrospective study supporting a prospective assessment

The presence of an intrahepatic cholangiocarcinoma (iCCA) in a cirrhotic liver is a contraindication for liver transplantation in most centers worldwide. Recent investigations have shown that "very early" iCCA (single tumors ≤2 cm) may have acceptable results after liver transplantation. This study further evaluates this finding in a larger international multicenter cohort. The study group was composed of those patients who were transplanted for hepatocellular carcinoma or decompensated cirrhosis and found to have an iCCA at explant pathology. Patients were divided into those with "very early" iCCA and those with "advanced" disease (single tumor >2 cm or multifocal disease). Between January 2000 and December 2013, 81 patients were found to have an iCCA at explant; 33 had separate nodules of iCCA and hepatocellular carcinoma, and 48 had only iCCA (study group). Within the study group, 15/48 (31%) constituted the "very early" iCCA group and 33/48 (69%) the "advanced" group. There were no significant differences between groups in preoperative characteristics. At explant, the median size of the largest tumor was larger in the "advanced" group (3.1 [2.5-4.4] versus 1.6 [1.5-1.8]). After a median follow-up of 35 (13.5-76.4) months, the 1-year, 3-year, and 5-year cumulative risks of recurrence were, respectively, 7%, 18%, and 18% in the very early iCCA group versus 30%, 47%, and 61% in the advanced iCCA group, P = 0.01. The 1-year, 3-year, and 5-year actuarial survival rates were, respectively, 93%, 84%, and 65% in the very early iCCA group versus 79%, 50%, and 45% in the advanced iCCA group, P = 0.02.

CONCLUSION

Patients with cirrhosis and very early iCCA may become candidates for liver transplantation; a prospective multicenter clinical trial is needed to further confirm these results. (Hepatology 2016;64:1178-1188).

Kinetics and stoichiometry of light-induced proton release and uptake from purple membrane fragments, Halobacterium halobium cell envelopes, and phospholipid vesicles containing oriented purple membrane

We have used flash spectroscopy and pH indicator dyes to measure the kinetics and stoichiometry of light-induced proton release and uptake by purple membrane in aqueous suspension, in cell envelope vesicles and in lipid vesicles. The preferential orientation of bacteriorhodopsin in opposite directions in the envelope and lipid vesicles allows us to show that uptake of protons occurs on the cytoplasmic side of the purple membrane and release on the exterior side. In suspensions of isolated purple membrane, approximately one proton per cycling bacteriorhodopsin molecule appears transiently in the aqueous phase with a half-rise time of 0.8 ms and a half-decay time of 5.4 ms at 21degreesC. In cell envelope preparations which consist of vesicles with a preferential orientation of purple membrane, as in whole cells, and which pump protons out, the acidification of the medium has a half-rise time of less than 1.0 ms, which partially relaxes in approx. 10 ms and fully relaxes after many seconds. Phospholipid vesicles, which contain bacteriorhodopsin preferentially oriented in the opposite direction and pump protons in, show an alkalinization of the medium with a time constant of approximately 10 ms, preceded by a much smaller and faster acidification. The alkalinization relaxes over many seconds. The initial fast acidification in the lipid vesicles and the fast relaxation in the envelope vesicles are accounted for by the misoriented fractions of bacteriorhodopsin. The time constants of the main effects, acidification in the envelopes and alkalinization in the lipid vesicles correlate with the time constants for the release and uptake of protons in the isolated purple membrane, and therefore show that these must occur on the outer and inner surface respectively. The slow relaxation processes in the time range of several seconds must be attributed to the passive back diffusion of protons through the vesicle membrane.

IL-17 stimulates the proliferation and differentiation of human mesenchymal stem cells: implications for bone remodeling

Interleukin-17 (IL-17) is a cytokine secreted primarily by T(H)-17 cells. Although IL-17 is primarily associated with the induction of tissue inflammation, the other biological roles of IL-17, including non-immune functions, have yet to be thoroughly explored. Here, we report that T-cell-produced IL-17 can induce proliferation of human bone marrow-derived mesenchymal stem cells (hMSCs) in a manner dependent on the generation of reactive oxygen species (ROS). Rac1 GTPase and NADPH oxidase 1 (Nox1) are activated by IL-17 to produce ROS, which in turn stimulates hMSC proliferation. The activation of the MEK-ERK pathway is also crucial for IL-17-dependent hMSC proliferation. TRAF6 and Act1 are required to activate Nox 1 and to phosphorylate MEK on IL-17 stimulation. Interestingly, IL-17 not only accelerates the proliferation of hMSCs, but also induces their migration, motility, and osteoblastic differentiation. Furthermore, IL-17 induces the expression of M-CSF and receptor activator of NF-kappaB ligand (RANKL) on hMSCs, thereby supporting osteoclastogenesis both in vivo and in vitro. On the basis of these results, we suggest that IL-17 can function as a signal to induce extensive bone turnover by regulating hMSC recruitment, proliferation, motility, and differentiation.

Effects of structure of beta-cyclodextrin-containing polymers on gene delivery

Linear cationic beta-cyclodextrin-based polymers (betaCDPs) are capable of forming polyplexes with nucleic acids and transfecting cultured cells. The betaCDPs are synthesized by the condensation of a diamino-cyclodextrin monomer A with a diimidate comonomer B. In this paper, the effects of polymer structure on polyplex formation, in vitro transfection efficiency and toxicity are elucidated. By comparison of the betaCDPs to polyamidines lacking cyclodextrins, the inclusion of a cyclodextrin moiety in the comonomer A units reduces the IC50s of the polymer by up to 3 orders of magnitude. The spacing between the cationic amidine groups is also important. Different polymers with 4, 5, 6, 7, 8, and 10 methylene units (betaCDP4, 5, 6, 7, 8, and 10) in the comonomer B molecule are synthesized. Transfection efficiency is dependent on comonomer B length with up to 20-fold difference between polymers. Optimum transfection is achieved with the betaCDP6 polymer. In vitro toxicity varied by 1 order of magnitude and the lowest toxicity is observed with betaCDP8. The LD40 of the betaCDP6 to mice is 200 mg/kg, making this polymer a promising agent for in vivo gene delivery applications.

Preparation of alginate beads for floating drug delivery system: effects of CO(2) gas-forming agents

Floating beads were prepared from a sodium alginate solution containing CaCO(3) or NaHCO(3) as gas-forming agents. The solution was dropped to 1% CaCl(2) solution containing 10% acetic acid for CO(2) gas and gel formation. The effects of gas-forming agents on bead size and floating properties were investigated. As gas-forming agents increased, the size and floating properties increased. Bead porosity and volume average pore size, as well as the surface and cross-sectional morphology of the beads were examined with Mercury porosimetry and Scanning Electron Microscopy. NaHCO(3) significantly increased porosity and pore diameter than CaCO(3). Incorporation of CaCO(3) into alginate solution resulted in smoother beads than those produced with NaHCO(3). Gel strength analysis indicated that bead strength decreased with increasing gas-forming agent from 9 to 4 N. Beads incorporating CaCO(3) exhibited significantly increased gel strength over control and NaHCO(3)-containing samples. Release characteristics of riboflavin as a model drug were studied in vitro. Release rate of riboflavin increased proportionally with addition of NaHCO(3). However, increasing weight ratios of CaCO(3) did not appreciably accelerate drug release. The results of these studies indicate that CaCO(3) is superior to NaHCO(3) as a gas forming agent in alginate bead preparations. The enhanced buoyancy and sustained release properties of CaCO(3)-containing beads make them an excellent candidate for floating drug dosage systems (FDDS).

Carbon partitioning to cellulose synthesis

This article discusses the importance and implications of regulating carbon partitioning to cellulose synthesis, the characteristics of cells that serve as major sinks for cellulose deposition, and enzymes that participate in the conversion of supplied carbon to cellulose. Cotton fibers, which deposit almost pure cellulose into their secondary cell walls, are referred to as a primary model system. For sucrose synthase, we discuss its proposed role in channeling UDP-Glc to cellulose synthase during secondary wall deposition, its gene family, its manipulation in transgenic plants, and mechanisms that may regulate its association with sites of polysaccharide synthesis. For cellulose synthase, we discuss the organization of the gene family and how protein diversity could relate to control of carbon partitioning to cellulose synthesis. Other enzymes emphasized include UDP-Glc pyrophosphorylase and sucrose phosphate synthase. New data are included on phosphorylation of cotton fiber sucrose synthase, possible regulation by Ca2+ of sucrose synthase localization, electron microscopic immunolocalization of sucrose synthase in cotton fibers, and phylogenetic relationships between cellulose synthase proteins, including three new ones identified in differentiating tracheary elements of Zinnia elegans. We develop a model for metabolism related to cellulose synthesis that implicates the changing intracellular localization of sucrose synthase as a molecular switch between survival metabolism and growth and/or differentiation processes involving cellulose synthesis.

Association study of transforming growth factor alpha (TGF alpha) TaqI polymorphism and oral clefts: indication of gene-environment interaction in a population-based sample of infants with birth defects

In this study of infants with isolated birth defects, 69 cleft palate only cases, 114 cleft lip with or without cleft palate cases, and 284 controls with noncleft birth defects (all born in Maryland between 1984 and 1992) were examined to test for associations among maternal exposures, genetic markers, and oral clefts. A significantly higher frequency of positive family history of birth defects among both groups of oral cleft cases compared with controls was seen in these data. While there was a modest increase in the less common C2 allele at the TaqI site in the transforming growth factor alpha (TGF alpha) locus among cleft palate only infants compared with the birth defect controls, the association appeared to reflect an underlying interaction between maternal smoking and infant genotype. This apparent gene-environment interaction was also found among those reporting no family history of any birth defect. Infants carrying the rarer C2 allele who were exposed to maternal smoking of 10 or fewer cigarettes per day showed a 6.16-fold increase in risk for cleft palate only (95% confidence interval 1.09-34.7), while similar infants whose mothers smoked more than 10 cigarettes per day showed an 8.69-fold higher risk (95% confidence interval 1.57-47.8). However, the dose-response relation was not significant.

Green-fluorescent protein as a new vital marker in plant cells

The green-fluorescent protein (GFP) from jellyfish Aequorea victoria has been used as a convenient new vital marker in various heterologous systems. However, it has been problematic to express GFP in higher eukaryotes, especially in higher plants. This paper reports that either a strong constitutive or a heat-shock promoter can direct the expression of GFP which is easily detectable in maize mesophyll protoplasts. In this single-cell system, bright green fluorescence emitted from GFP is visible when excited with UV or blue light even in the presence of blue fluorescence from the vacuole or the red chlorophyll autofluorescence from chloroplasts using a fluorescence microscope. No exogenous substrate, co-factor, or other gene product is required. GFP is very stable in plant cells and shows little photobleaching. Viable cells can be obtained after fluorescence-activated cell sorting based on GFP. The paper further reports that GFP can be detected in intact tissues after delivering the constructs into Arabidopsis leaf and root by microprojectile bombardment. The successful detection of GFP in plant cells relies on the use of a universal transcription enhancer from maize or the translation enhancer from tobacco mosaic virus (TMV) to boost the expression. This new reporter could be used to monitor gene expression, signal transduction, co-transfection, transformation, protein trafficking and localization, protein-protein interaction, cell separation and purification, and cell lineage in higher plants.

Enteric beta-defensin: molecular cloning and characterization of a gene with inducible intestinal epithelial cell expression associated with Cryptosporidium parvum infection

A growing body of evidence suggests that endogenous antibiotics contribute to the innate defense of mammalian mucosal surfaces. In the cow, beta-defensins constitute a large family of antibiotic peptides whose members have been previously isolated from the respiratory and oral mucosa, as well as circulating phagocytic cells. A novel bovine genomic clone with beta-defensin-related sequence [corrected] related to those of these alpha-defensins was isolated and characterized. The corresponding cDNA was isolated from a small intestinal library; its open reading frame predicts a deduced sequence of a novel beta-defensin, which we designate enteric beta-defensin (EBD). Northern blot analysis of a variety of bovine tissues revealed that EBD mRNA is highly expressed in the distal small intestine and colon, anatomic locations distinct from those for previously characterized beta-defensins. EBD mRNA was further localized by in situ hybridization to epithelial cells of the colon and small intestinal crypts. Infection of two calves with the intestinal parasite Cryptosporidium parvum induced 5- and 10-fold increases above control levels of EBD mRNA in intestinal tissues. An anchored-PCR strategy was used to identify other beta-defensin mRNAs expressed in the intestine. In addition to that of EBD, several low-abundance cDNAs which corresponded to other beta-defensin mRNAs were cloned. Most of these clones encoded previously characterized beta-defensins or closely related isoforms, but two encoded a previously uncharacterized prepro-beta-defensin. Northern blot evidence supported that all of these other beta-defensin genes are expressed at levels lower than that of the EBD gene in enteric tissue. Furthermore, some of these beta-defensin mRNAs were abundant in bone marrow, suggesting that in enteric tissue their expression may be in cells of hematopoietic origin. Extracts of small intestinal mucosa obtained from healthy cows have numerous active chromatographic fractions as determined by an antibacterial assay, and one peptide was partially purified. The peptide corresponded to one of the low-abundance cDNAs. This study provides evidence of beta-defensin expression in enteric tissue and that the mRNA encoding a major beta-defensin of enteric tissue, EBD, is inducibly expressed in enteric epithelial cells. These findings support the proposal that beta-defensins may contribute to host defense of enteric mucosa.

CREB-binding protein and histone deacetylase regulate the transcriptional activity of Kaposi's sarcoma-associated herpesvirus open reading frame 50

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) open reading frame 50 (ORF50) encodes a viral transcriptional activator, which binds to the KSHV promoter and stimulates the transcription of viral early and late genes, thus activating the lytic cycle of KSHV. We report here that KSHV ORF50 binds to the cellular proteins CREB-binding protein (CBP) and histone deacetylase (HDAC) and these binding events modulate ORF50-activated viral transcription. Binding of ORF50 to CBP and HDAC activates and represses, respectively, ORF50-mediated viral transcription. KSHV ORF50 was shown to bind to the C/H3 domain and the C-terminal transcriptional activation domain of CBP, while CBP bound to the amino-terminal basic domain and the carboxyl-terminal transactivation domain of ORF50. The LXXLL motif within the transcriptional activation domain of ORF50 is reminiscent of the CBP-binding sequence found in nuclear receptor proteins. The adenovirus E1A protein, which also binds to the C/H3 domain of CBP, repressed the transcriptional activation activity of ORF50. The cellular protein c-Jun, which binds to the kinase-induced activation domain of ORF50, stimulated ORF50-mediated viral transcription. The HDAC1-interacting domain of ORF50 was shown to be a central proline-rich sequence. Our data provide a framework for delineating the regulatory mechanisms used by KSHV to modulate its transcription and replication through interaction with both histone acetyltransferases and HDACs.

MRI phenotype is associated with response to doxorubicin and cyclophosphamide neoadjuvant chemotherapy in stage III breast cancer

BACKGROUND

The preferred management for women with stage II or locally advanced breast cancer (LABC) is neoadjuvant chemotherapy. Pathologic response to chemotherapy has been shown to be an excellent predictor of outcome. Surrogates that can predict pathologic response and outcome will fuel future changes in management. Magnetic resonance imaging (MRI) demonstrates that patients with LABC have distinct tumor patterns. We investigated whether or not these patterns predict response to therapy.

METHODS

Thirty-three women who received neoadjuvant doxorubicin and cyclophosphamide chemotherapy for 4 cycles and serial breast MRI scans before and after therapy were evaluated for this study. Response to therapy was measured by change in the longest diameter on the MRI.

RESULTS

Five distinct imaging patterns were identified: circumscribed mass, nodular tissue infiltration diffuse tissue infiltration, patchy enhancement, and septal spread. The likelihood of a partial or complete response as measured by change in longest diameter was 77%, 37.5%, 20%, and 25%, respectively.

CONCLUSIONS

MRI affords three-dimensional characterization of tumors and has revealed distinct patterns of tumor presentation that predict response. A multisite trial is being planned to combine imaging and genetic information in an effort to better understand and predict response and, ultimately, to tailor therapy and direct the use of novel agents.

Unfolding and refolding of a purified precursor protein during import into isolated mitochondria

A purified mitochondrial precursor protein unfolds to a protease-sensitive conformation at the surface of isolated mitochondria before being imported into the organelles. This unfolding is stimulated by a potential across the mitochondrial inner membrane, but does not require ATP. In contrast, import of the surface-bound unfolded precursor requires ATP, but no potential; it is accompanied by a refolding inside the mitochondria.

Timely translation during the mouse oocyte-to-embryo transition

In the mouse, completion of oocyte maturation and the initiation of preimplantation development occur during transcriptional silence and depend on the presence and translation of stored mRNAs transcribed in the growing oocyte. The Spin gene has three transcripts, each with an identical open reading frame and a different 3′ untranslated region (UTR). (Beta)-galactosidase-tagged reporter transcripts containing each of the different Spin 3′UTRs were injected into oocytes and zygotes and (beta)-galactosidase activity was monitored. Results from these experiments suggest that differential polyadenylation and translation occurs at two critical points in the oocyte-to-embryo transition - upon oocyte maturation and fertilization - and is dependent on sequences in the 3′UTR. The stability and mobility shifts of ten other maternal transcripts were monitored by reprobing a northern blot of oocytes and embryos collected at 12 hour intervals after fertilization. Some are more stable than others and the upward mobility shift associated with polyadenylation correlates with the presence of cytoplasmic polyadenylation elements (CPEs) within about 120 nucleotides of the nuclear polyadenylation signal. A survey of the 3′ UTRs of expressed sequence tag clusters from a mouse 2-cell stage cDNA library indicates that about one third contain CPEs. We suggest that differential transcript stability and a translational control program can supply the diversity of protein products necessary for oocyte maturation and the initiation of development.

Hepatic steatosis in chronic hepatitis C virus infection: prevalence and clinical correlation

BACKGROUND AND AIMS

Hepatic steatosis is a histological characteristic in patients with chronic hepatitis C virus (HCV) infection. The aim of this study was to evaluate the prevalence of hepatic steatosis in Chinese patients with chronic hepatitis C, and to look for possible correlation with various histopathological changes and to look for possible correlation with various clinical and pathologic variables.

METHODS

One hundred and six patients were enrolled, and patients with alcoholism or diabetes mellitus were excluded. Clinical, biochemical and virologic data, including HCV genotype and serum HCV-RNA titer and histological findings, were compared between patients with and without hepatic steatosis.

RESULTS

Fifty-five (52%) of the 106 patients with chronic hepatitis C had hepatic steatosis. Patients with hepatic steatosis had significantly higher mean serum levels of triglyceride and gamma-glutamyl transpeptidase, higher body mass index, and a higher incidence of obesity compared with patients without hepatic steatosis. No significant differences in serum HCV-RNA titer and HCV genotype or the response to interferon therapy were noted between the two groups. Histological analysis showed patients with hepatic steatosis had a significantly higher mean fibrotic score than patients without hepatic steatosis (1.9 +/- 1.2 vs 1.3 +/- 1.0; P = 0.016). There were no significant differences in the severity of necroinflammation, the presence of lymphoid aggregation/follicle or bile duct damage between the two groups. Multivariate logistic regression analysis showed that independent predictors associated with hepatic steatosis were obesity or a histology fibrotic score of > or = 2.

CONCLUSION

It was found that 52% of Chinese patients with chronic hepatitis C had hepatic steatosis. Patients with hepatic steatosis were more frequently obese and had more severe hepatic fibrosis.

One hundred and eleven liver resections for hilar bile duct cancer

A positive correlation between absence of residual tumor at resection margins and long-term survival in the treatment of hilar bile duct carcinoma has encouraged some surgeons to use a more radical approach, including liver/portal vein resection and combined pancreatoduodenectomy. However, if liver resection is associated with significant morbidity and mortality, it may not produce any overall benefit. This review was undertaken in an attempt to determine whether liver resection is a safe procedure and whether if has any beneficial effect over that of local bile duct excision alone, in terms of achieving curative resection and long-term survival. The records of 151 patients with hilar bile duct carcinoma surgically treated between June 1989 and December 1997 at the Asan Medical Center, Seoul, were retrospectively analyzed. Surgical resection was possible in 128 patients. The remaining 23 patients had surgical palliative drainage. Local bile duct excision alone was performed in 17 patients. Liver resection for tumor extending to secondary bile ducts or hepatic parenchyma was performed in 111 patients; portal vein resection was necessary in 29 of these 111 patients (26.1%) and pancreatoduodenectomy was combined in 18 patients (16.2%). Seven patients died during hospitalization after liver resection, an operative mortality of 6.3%. Margins of bile duct resection were free of tumor on histologic examination in 4 of the 17 local bile duct excisions, but in 86 of the 111 liver resections. The cumulative survival rate after local bile duct excision was 85.7% at 1 year, 42.9% at 2 years, 21.4% at 3 years, and 0% at 4 years. However, the survival rate after liver resection (excluding operative mortality) was 97.1% at 1 year, 72.8% at 2 years, 55.3% at 3 years, and 24.0% at 5 years. Survival and the percentage of patients with tumor-free resection margins after liver resection were superior to those after local bile duct excision. Resection of hilar bile duct carcinoma offers long-term survival only when surgery is aggressive and includes liver resection.

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.

Avoiding a spanning cluster in percolation models

When dynamics in a system proceeds under suppressive external bias, the system can undergo an abrupt phase transition, as can happen when an epidemic spreads. Recently, an explosive percolation (EP) model was introduced to understand such phenomena. The order of the EP transition has not been clarified in a unified framework covering low-dimensional systems and the mean-field limit. We introduce a stochastic model in which a rule for dynamics is designed to avoid the formation of a spanning cluster through competitive selection in Euclidean space. We use heuristic arguments to show that in the thermodynamic limit and depending on a control parameter, the EP transition can be either continuous or discontinuous if d < d(c) and is always continuous if d ≥ d(c), where d(c) is the spatial dimension and d is the upper critical dimension.

ABO-Incompatible Adult Living Donor Liver Transplantation Under the Desensitization Protocol With Rituximab

ABO incompatibility is no longer considered a contraindication for adult living donor liver transplantation (ALDLT) due to various strategies to overcome the ABO blood group barrier. We report the largest single-center experience of ABO-incompatible (ABOi) ALDLT in 235 adult patients. The desensitization protocol included a single dose of rituximab and total plasma exchange. In addition, local graft infusion therapy, cyclophosphamide, or splenectomy was used for a certain time period, but these treatments were eventually discontinued due to adverse events. There were three cases (1.3%) of in-hospital mortality. The cumulative 3-year graft and patient survival rates were 89.2% and 92.3%, respectively, and were comparable to those of the ABO-compatible group (n = 1301). Despite promising survival outcomes, 17 patients (7.2%) experienced antibody-mediated rejection that manifested as diffuse intrahepatic biliary stricture; six cases required retransplantation, and three patients died. ABOi ALDLT is a feasible method for expanding a living liver donor pool, but the efficacy of the desensitization protocol in targeting B cell immunity should be optimized.

The transcriptional activity of cAMP response element-binding protein-binding protein is modulated by the latency associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus

A multifunctional transcription co-activator, cAMP response element-binding protein-binding protein (CBP)interacts with a number of cellular factors and participates in cell growth, transformation, and development. It is also targeted by many viral proteins for their transcriptional activity or for the regulation of cellular processes. Here, we report that the C/H3 region of CBP is targeted by the latency associated nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus (KSHV). LANA interferes with the interaction between CBP and c-Fos, a representative C/H3 region binding, cellular transcription factor, in vivo and in vitro. In addition, we found that LANA inhibits the transcriptional activity and the in vitro histone acetyltransferase activity of CBP, suggesting that LANA modulates the global transcriptional activities of infected cells through the interaction with CBP. These results indicate that KSHV follows one of the conserved strategies, which other viruses utilize for influencing the cellular processes.