Impact of Positive Donor-Specific HLA Antibodies Crossmatch on Graft Survival in ABO-Incompatible Liver-Kidney Transplantation: A Case Report.

We present a patient with positive donor-specific antibodies (DSA) and crossmatch of ABO-incompatible (ABOi) combined liver and kidney transplantation (CLKT). Antibody-mediated rejection did not occur and the graft had survived for over one year at the time of writing without infectious complications. A 56-year-old man with positive DSA and positive crossmatch underwent living donor CLKT. The preoperative protocol for ABOi consisted of a single dose of rituximab and total plasma exchange (TPE). The result of anti-B antibody titer for IgG was 1:32. The evaluations of complement-dependent cytotoxicity and flow cytometry cross-match revealed a change from T+/B+ to T-/B+. The patient required adult living donor CLKT. Acute rejection episodes were treated using antithymocyte globulin, and the kidney required 7 days' treatment to recover. No further rejection and infectious episodes have been observed in past 13 months since the transplant. DSA and crossmatches are important for antibody detection and analysis. In the rituximab era, TPE can be used to achieve a successful decrease in antibody titer. In countries with a severe shortage of cadaveric organ donors, it may be possible to select ABOi candidate donors with positive DSA and crossmatch.

Rapidly increasing liver progenitor cell numbers in human regenerating liver after portal vein ligation and liver partition.

BACKGROUND: Liver regeneration is dependent on the proliferation of hepatocytes. Hepatic progenitor cells are intra-hepatic precursor cells capable of differentiating into hepatocytes or biliary cells. Although liver progenitor cell proliferation during the regenerative process has been observed in animal models of severe liver injury, it has never been observed in vivo in humans because it is unethical to take multiple biopsy specimens for the purpose of studying the proliferation of liver progenitor cells and the roles they play in liver regeneration. Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a staged procedure for inducing remnant liver hypertrophy so that major hepatectomy can be performed safely. This staged procedure allows for liver biopsy specimens to be taken before and after the liver begins to regenerate. CASE PRESENTATION: The liver progenitor cell proliferation is observed in a patient undergoing ALPPS for a metastatic hepatic tumour. Liver biopsy is acquired before and after ALPPS for the calculation of average number of liver progenitor cell under high magnification examination by stain of immunomarkers. This is the first in vivo evidence of growing liver progenitor cells demonstrated in a regenerating human liver.

Predictive value of nodal maximum standardized uptake value of pretreatment [18F]fluorodeoxyglucose positron emission tomography imaging in patients with esophageal cancer.

We retrospectively reviewed 102 patients with esophageal cancer (97.1% squamous cell carcinoma, 96.1% stage III) received FDG-PET staging and were treated by chemoradiotherapy with or without resection to assess whether the pretreatment [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) maximum standardized uptake value (SUVmax) of the primary tumor and metastatic lymph nodes can predict the prognosis of patients with esophageal cancer. Receiver operating characteristic analysis was performed to find the cutoff values for primary tumor SUVmax and nodal SUVmax. The influence of clinical factors including primary tumor SUVmax and nodal SUVmax on local progression-free survival, nodal progression-free survival (NPFS), distant metastases-free survival (DMFS), and overall survival (OS) were evaluated using univariate and multivariate analyses. A total of 40 patients received esophagectomy after neoadjuvant chemoradiotherapy (trimodality), while 62 patients received definitive chemoradiotherapy (dCRT). The median follow-up was 26.4 months. The SUVmax of primary tumor had no significant predictive value on all outcomes, while the SUVmax of metastatic lymph nodes had predictive value on several outcomes. High nodal SUVmax (≥7) predicted for worse outcomes than low nodal SUVmax (<7) in the patients who received dCRT (two-year DMFS, 17% vs. 92%, P < 0.001; NPFS, 14% vs. 81%, P = 0.001; OS, 21% vs. 50%, P = 0.003), but not in those received trimodality. On multivariate analysis of patients receiving dCRT, nodal SUVmax was the strongest independent predictor on DMFS (hazard ratio [HR] 13.93, P < 0.001), NPFS (HR 3.99, P = 0.026), PFS (HR 2.90, P = 0.003), and OS (HR 3.80, P = 0.001). High pretreatment nodal SUVmax predicts worse treatment outcomes for the patients treated with dCRT.

Betel Nut Chewing Is Associated With Reduced Tacrolimus Concentration in Taiwanese Liver Transplant Recipients.

PURPOSE: Studies have shown that arecoline, the major alkaloid component of betel nuts, alters the activity of enzymes in the cytochrome P450 (CYP-450) family. Tacrolimus, an immunosuppressant that protects against organ rejection in transplant recipients, not only is mainly metabolized by CYP3A enzymes but also has a narrow therapeutic range. We aimed to investigate whether dose-adjusted blood trough levels of tacrolimus differed over time between betel nut-chewing and non-betel nut-chewing liver transplant recipients. METHODS: In this retrospective case-control study, 14 active betel nut-using liver recipients were matched at a 1:2 ratio to 28 non-betel nut-using liver recipients by sex, age, graft source, duration of follow-up after liver transplantation, and estimated glomerular filtration rate. Differences in liver function index, renal function index, and dose-adjusted blood trough levels of tacrolimus over an 18-month period were compared between the 2 groups by using the Generalized Estimating Equation approach. RESULTS: Dose-adjusted blood trough levels of tacrolimus tended to be significantly (P = .04) lower in betel nut chewers (mean = 0.81, medium = 0.7, 95% confidence interval [CI] = 0.73 to 0.90) than in nonchewers (mean = 1.12, medium = 0.88, 95% CI = 1.03 to 1.22) during the 18-month study period. However, there was no significant difference in renal and liver function index between the 2 groups. CONCLUSION: Liver transplant recipients receiving tacrolimus tend to have lower blood trough levels of the drug over time if they chew betel nuts.

Predictors of Biliary Leakage After T-Tube Removal in Living Donor Liver Transplantation Recipients.

BACKGROUND: Biliary leakage after T-tube removal is a frequent cause of morbidity in liver transplant recipients. The aim of this study was to determine the factors that predict the development of biliary leakage after T-tube removal in living donor liver transplantation (LDLT) recipients. METHODS: Of the 144 patients who underwent LDLT with right-lobe liver grafts during the period January 2007 to May 2013 at a single medical center, 40 received biliary anastomosis with T-tube placement. Subjects were grouped into either a biliary leakage or non-biliary leakage group on the basis of the presence or absence of abdominal symptoms associated with signs of peritoneal irritation after T-tube removal. Recipient, graft, operative, and postoperative factors were included in a forward, stepwise multiple logistic regression model to identify the most important risk factors for biliary leakage after T-tube removal. RESULTS: Biliary leakage developed in 9 (22.5%) patients after T-tube removal. Risk factors associated with biliary leakage included the number of abdominal surgeries performed [odds ratio (OR) = 12.6, 95% confidence interval (CI): 2.1-20.4] and duration of T-tube placement (OR = 6.9, 95% CI: 1.2-10.7). CONCLUSIONS: Biliary leakage after T-tube removal is associated with significant morbidity in LDLT recipients. We suggest that T-tube placement be used sparingly in LDLT biliary reconstruction. When used, a T-tube should not be removed earlier than 8 months after placement, especially in recipients who have received primary abdominal surgery.

Liver transplantation in patients infected with gram-negative bacteria: non-Acinetobacter baumannii and Acinetobacter baumannii.

BACKGROUND: The current study investigated risk factor related to gram-negative bacterial (GNB) infection by Acinetobacter baumannii and non-A baumannii groups, in liver transplantation (OLT) recipients. MATERIALS AND METHODS: All patients with OLT and their living donors were analyzed retrospectively. After excluding those with Gram-positive and fungal infections 89 patients remained in the study including 59 who were noninfected and 30 with GNB infection. The risk factors for GNB infection were classified into the preoperative versus the postoperative periods. RESULTS: GNB-infected patients were classified as non-A baumannii versus A baumannii (15 patients per group). A significant difference was observed in the numbers of intensive care and hospitalized days, hemodialysis requirement, and reoperation frequency compared with the noninfected group. Infection also correlated with hospital mortality, overall survival, and Model for End-Stage Liver Disease (MELD) scores with significance upon univariate but only the last feature on multivariate analysis. CONCLUSIONS: Preoperative MELD scores were more likely to be higher among the non-A baumannii compared with the A baumannii-infected group. However, the 1-year survival of the A baumannii-infected subjects was lower than that of the non-A baumannii infected group.

Extracorporeal membrane oxygenation support in potential organ donors for brain death determination.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) must be applied in early stages to perfuse organs before donation in order to expand the donor pool. The aim of this study was to examine the benefits of ECMO for potential organ donors with multiple complications. MATERIALS AND METHODS: This retrospective review describes patients with ECMO support who were on the verge of brain death and therefore potential subjects for organ donation. RESULTS: Six organ donors with severe neurological damage under ECMO support completed the procedures, namely, two women and four men of ages 19 to 58 years (mean, 32 years). Three donors completed the brain-death determination procedure, one failed the procedure, and two experienced cardiac asystole prior to the procedure and were unable to be declared dead even after resuscitation. Nine kidneys and three livers were successfully retrieved from 5/6 donors, leading to 11 successful transplantations: eight kidneys, two livers, and one simultaneous kidney-liver transplantations. The organs functioned well and the recipients made full recoveries. CONCLUSIONS: ECMO allows for the maintenance of abdominal organ tissue perfusion without warm ischemia before organ procurement, providing sufficient time for safe organ donation procedures and reducing the risk of unpredictable cardiac arrest that could result in the donor death and graft loss.

Electron tomography of frozen-hydrated isolated triad junctions.

Cryoelectron microscopy and tomography have been applied for the first time to isolated, frozen-hydrated skeletal muscle triad junctions (triads) and terminal cisternae (TC) vesicles derived from sarcoplasmic reticulum. Isolated triads were selected on the basis of their appearance as two spherical TC vesicles attached to opposite sides of a flattened vesicle derived from a transverse tubule (TT). Foot structures (ryanodine receptors) were resolved within the gap between the TC vesicles and TT vesicles, and some residual ordering of the receptors into arrays was apparent. Organized dense layers, apparently containing the calcium-binding protein calsequestrin, were found in the lumen of TC vesicles underlying the foot structures. The lamellar regions did not directly contact the sarcoplasmic reticulum membrane, thereby creating an approximately 5-nm-thick zone that potentially constitutes a subcompartment for achieving locally elevated [Ca(2+) ] in the immediate vicinity of the Ca(2+)-conducting ryanodine receptors. The lumen of the TT vesicles contained globular mass densities of unknown origin, some of which form cross-bridges that may be responsible for the flattened appearance of the transverse tubules when viewed in cross-section. The spatial relationships among the TT membrane, ryanodine receptors, and calsequestrin-containing assemblage are revealed under conditions that do not use dehydration, heavy-metal staining, or chemical fixation, thus exemplifying the potential of cryoelectron microscopy and tomography to reveal structural detail of complex subcellular structures.

Topology of the mitochondrial inner membrane: dynamics and bioenergetic implications.

Electron tomography indicates that the mitochondrial inner membrane is not normally comprised of baffle-like folds as depicted in textbooks. In actuality, this membrane is pleomorphic, with narrow tubular regions connecting the internal compartments (cristae) to each other and to the membrane periphery. The membrane topologies observed in condensed (matrix contracted) and orthodox (matrix expanded) mitochondria cannot be interconverted by passive folding and unfolding. Instead, transitions between these morphological states likely involve membrane fusion and fission. Formation of tubular junctions in the inner membrane appears to be energetically favored, because they form spontaneously in yeast mitochondria following large-amplitude swelling and recontraction. However, aberrant, unattached, vesicular cristae are also observed in these mitochondria, suggesting that formation of cristae junctions depends on factors (such as the distribution of key proteins and/or lipids) that are disrupted during extreme swelling. Computer modeling studies using the "Virtual Cell" program suggest that the shape of the inner membrane can influence mitochondrial function. Simulations indicate that narrow cristae junctions restrict diffusion between intracristal and external compartments, causing depletion of ADP and decreased ATP output inside the cristae.

A new look at kinetochore structure in vertebrate somatic cells using high-pressure freezing and freeze substitution.

Three decades of structural analysis have produced the view that the kinetochore in vertebrate cells is a disk-shaped structure composed of three distinct structural domains. The most prominent of these consists of a conspicuous electron opaque outer plate that is separated by a light-staining electron-translucent middle plate from an inner plate associated with the surface of the pericentric heterochromatin. Spindle microtubules terminate in the outer plate and, in their absence, a conspicuous corona of fine filaments radiates from the cytoplasmic surface of this plate. Here we report for the first time the ultrastructure of kinetochores in untreated and Colcemid-treated vertebrate somatic (PtK1) cells prepared for optimal structural preservation using high-pressure freezing and freeze substitution. In serial thin sections, and electron tomographic reconstructions, the kinetochore appears as a 50-75 nm thick mat of light-staining fibrous material that is directly connected with the more electron-opaque surface of the centromeric heterochromatin. This mat corresponds to the outer plate in conventional preparations, and is surrounded on its cytoplasmic surface by a conspicuous 100-150 nm wide zone that excludes ribosomes and other cytoplasmic components. High magnification views of this zone reveal that it contains a loose network of light-staining, thin (<9 nm diameter) fibers that are analogous to the corona fibers in conventional preparations. Unlike the chromosome arms, which appear uniformly electron opaque, the chromatin in the primary constriction appears mottled. Since the middle plate is not visible in these kinetochore preparations this feature is likely an artifact produced by extraction and coagulation during conventional fixation and/or dehydration procedures.

Capsid protein of cucumber mosaic virus accumulates in the nuclei and at the periphery of the nucleoli in infected cells.

Tobacco leaves infected with two strains and their reciprocal RNA 3 pseudorecombinants of cucumber mosaic virus (CMV) were examined by immunoelectron microscopy. In addition to the regular detection of CMV in the cytoplasm and vacuoles, immunogold-labelled viral proteins occurred commonly in the nuclei and at the periphery of impacted nucleoli in all four samples examined. However, viral protein was present only in the euchromatin region and rare in the heterochromatin region.