Bioengineering in organ transplantation: targeting the liver

About 27,000 deaths are registered annually in the United States due to liver disease. At this time, the only definitive treatment of hepatic failure is orthotopic transplantation. However, there is a critical shortage of organs with the total waiting list for all organs currently at 100,000 requests. The number is increasing by 5% every year. Given that only organs in pristine condition are transplantable and that the hidden demand for organs as an anti-aging solution will be many times the current figures, orthotopic transplantation will always remain a limited pool. The increasing donor organ shortage requires consideration of alternative emerging technologies. Regenerative medicine may offer novel strategies to treat patients with end-stage organ failure. The ultimate aim of cell transplantation, tissue engineering, and stem cells is to regenerate tissues and organs. With the development of whole organ decellularization methods, the equation of organ shortage may dramatically change in the near future. Decellularized organs provide the ideal transplantable scaffold with all the necessary microstructure and extracellular cues for cell attachment, differentiation, vascularization, and function. New techniques to re-engineer organs may have major implications for the fields of drug discovery, regeneration biology, and ultimately organ transplantation. In this review we have provided an overview of complementary approaches to study and enhance the success of organ repopulation strategies creating new grafts/organs for transplantation.

Natural history of Upshaw-Schulman syndrome based on ADAMTS13 gene analysis in Japan

Upshaw-Schulman syndrome (USS) is an extremely rare hereditary deficiency of ADAMTS13 activity, termed congenital TTP. The clinical signs are usually mild during childhood, often with isolated thrombocytopenia. But their symptoms become more evident when patients have infections or get pregnant. We identified 43 USS-patients in Japan, who ranged in age from early childhood to 79 years of age. Analysing the natural history of these USS patients based on ADAMTS13 gene mutations may help characterise their clinical phenotypes. Severe neonatal jaundice that requires exchange blood transfusion, a hallmark of USS, was found in 18 of 43 patients (42%). During childhood, 25 of 43 patients were correctly diagnosed with USS without gender disparity. These 25 patients were categorised as having 'the early-onset phenotype'. Between 15 and 45 years of age, 15 were correctly diagnosed, and, interestingly, they were all female. The remaining three patients were male and were diagnosed when they were older than 45 years of age, suggesting that they were 'the late-onset phenotype'. Two of these three males developed sudden overt TTP when they were 55 and 63 years old, respectively. These two men had two different homozygous ADAMTS13 gene mutations, p.R193W/p.R193W and p.C1024R/p.C1024R, respectively. Both of which were not discovered in the US or Western countries. In vitro expression studies showed that these two proteins were consistently secreted into the culture medium but to a lesser extent and with reduced activity compared to the wild-type protein. Our results indicate that 'the late-onset phenotype' of USS is formed with ethnic specificity.

Continuous-wave and mode-locked lasers on the base of partially disordered crystalline Yb3+:{YGd2}[Sc2](Al2Ga)O12 ceramics

We present cw and mode-locked laser operations on the base of partially disordered crystalline Yb(3+):{YGd(2)}[Sc(2)](Al(2)Ga)O(12) ceramics. In continuous-wave laser operations, the average power of 2.9 W at the wavelength of 1051 nm and 2.8 W at the wavelength of 1031 nm with above 40% optical-to-optical efficiencies were achieved. In mode-locked laser operation, pulses as short as 69 fs with the average power of 820 mW was also obtained.

Prophylactic fresh frozen plasma may prevent development of hepatic VOD after stem cell transplantation via ADAMTS13-mediated restoration of von Willebrand factor plasma levels

We initially conducted a multicenter, randomized trial (n=43), and subsequently a questionnaire study (n=209) of participating hospitals, to evaluate whether infused fresh frozen plasma (FFP) could prevent the occurrence of hepatic veno-occlusive disease (VOD) after stem cell transplantation (SCT). Forty-three patients were divided into two groups: 23 receiving FFP infusions and 20 not receiving it. VOD developed in three patients not receiving FFP. Plasma von Willebrand factor (VWF) antigen levels were lower at days 0, 7 and 28 after SCT in patients receiving FFP than in those not receiving it, whereas plasma ADAMTS13 activity (ADAMTS13:AC) did not differ between them. Plasma VWF multimer (VWFM) was demonstrated to be defective in the high approximately intermediate VWFM during the early post-SCT phase, but there was a significant increase in high VWFM just before VOD onset. This suggests that a relative enzyme-to-substrate (ADAMTS13/high-VWFM) imbalance is involved in the pathogenesis of VOD. To strengthen this hypothesis, the incidence of VOD was apparently lower in patients receiving FFP infusions than in those not receiving it (0/23 vs 3/20) in the randomized trial. Further, the results combined with the subsequent questionnaire study (0/36 vs 11/173) clearly showed the incidence to be statistically significant (0/59 vs 14/193, P=0.033).

High-efficiency 1040 and 1078 nm laser emission of a Yb:Y2O3 ceramic laser with 976 nm diode pumping

We report a high-efficiency diode-end-pumped polycrystalline Yb:Y2O3 ceramic laser. Pumped by a 976 nm laser diode bar and with an absorbed pump power of 2.8 W, cw output power of 1.74 W at 1078 nm, and 0.73 W at 1040 nm were obtained. The slope efficiency was measured to be 82.4% for the 1078 nm laser emission and 57.1% for the 1040 nm laser emission.

Diode-pumped mode-locked Yb(3+):Lu(2)O(3) ceramic laser

We report a diode-pumped passively mode-locked Yb(3+):Lu(2)O(3) ceramic laser by use of a semiconductor saturable absorber mirror. Almost transform-limited 357 fs pulses at the center wavelength of 1033.5 nm with a maximum average power of 352 mW are obtained. The efficiency against the absorbed pump power is as high as 32% by use of a laser-diode pumping and the repetition rate is 97 MHz. This is the first demonstration of a diode-pumped mode-locked Yb(3+):Lu(2)O(3) ceramic laser to our knowledge.

Preliminary laboratory based diagnostic criteria for immune thrombocytopenic purpura: evaluation by multi-center prospective study

BACKGROUND

We proposed diagnostic criteria for immune thrombocytopenic purpura (ITP) by modifying the existing guidelines for diagnosis of ITP and by incorporating laboratory tests found useful for predicting its diagnosis, for example erythrocyte count, leukocyte count, anti-GPIIb/IIIa antibody-producing B cells, platelet-associated anti-GPIIb/IIIa antibodies, percentage of reticulated platelets, and plasma thrombopoietin.

OBJECTIVE AND METHODS

To validate our criteria, we conducted a multi-center prospective study involving 112 patients with thrombocytopenia and a morphologically normal peripheral blood film at the first visit. Each patient underwent a physical examination, routine laboratory tests, and specialized tests for the anti-GPIIb/IIIa antibody response and platelet turnover.

RESULTS

Ninety-one patients (81%) satisfied the proposed criteria at first visit. Clinical diagnosis was made by skilled hematologists > 6 months after the first visit; ITP was diagnosed in 88 patients and non-ITP disorders in 24. The proposed criteria had 98% sensitivity, 79% specificity, a 95% positive predictive value, and a 90% negative predictive value. A relatively low specificity appears to be attributed to a few patients who had both ITP and aplastic anemia or myelodysplastic syndrome.

CONCLUSIONS

Our preliminary diagnostic criteria based on ITP-associated laboratory findings were useful for the differential diagnosis of ITP, but additional evaluations and modifications will be necessary to develop criteria that can be used routinely.

[Quality control (QC) of CT on rail system (FOCAL Unit) with a micro-multi leaf collimator (mMLC) using new GafChromic film for stereotactic radiotherapy]

PURPOSE

Recent years, CT on rail system was reported to be useful as a tool for image-guided radiotherapy (IGRT). This system was clinically developed with the aim of stereotactic irradiation (STI) for brain, lung, liver, prostate and other sites. Quality assurance and quality control (QC) is an important issue in CT on rail system to assure geometric accuracies. The purpose of this study is to estimate the geometric accuracies of our CT on rail system using a detachable micro-multi leaf collimator (mMLC) with new type radiochromic films. Carrying out our original QC program, translational errors, setup reproducibility, beam misalignment and beam characteristics were evaluated.

METHODS AND MATERIALS

We have studied with CT on rail system (FOCAL unit, Toshiba Medical systems, Tokyo, Japan) and mMLC unit (Accuknife, Direx Inc., Tokyo, Japan). We have developed original alignment phantom and small steel markers (2 mm phi) were implanted on its surface at certain intervals. Firstly, we have evaluated the accuracy of self-moving CT gantry and CT resolutions for cranio-caudal directions by changing slice thickness. And then using the phantom, we have measured the accuracy and reproducibility of geometric isocenter of the linac side and the CT gantry side by scanning the phantom. We have also measured the geometric changes of the common treatment couch by weight-loaded test (up to 135 kgw). To estimate dosimetric and geometric accuracies with the mMLC unit, the misalignment of the beam axes (gantry, collimator and couch rotation axis), mMLC leaf positions, and dose distributions for the verification plan were measured with new type GafChromic films (GafChromic-RTQA, ISP Inc., USA) and cylindrical phantom. The dose characteristics of the GafChromic film were also evaluated.

RESULTS

The reproducibility of the self-moving CT gantry have a good agreement within 1 mm. Weight-load test have shown a good reliability within 2 mm at the common treatment couch. The translational precision of the common treatment couch was 0.0 +/- 0.1 mm at linac side and -0.2 +/- 0.5 mm at CT gantry side. The misalignments of beam axes have been kept within 0.4 mm at maximum. Gap test have shown the accuracies of the mMLC leaf positions, which is needed to keep within 1 mm by a routine calibration.

CONCLUSIONS

To practice quality control program for the FOCAL unit and the mMLC unit is essential for a regular interval to reduce systematic errors. New type radiochromic film would be useful for a verification tool as alternative to conventional film.

Naturally arising Foxp3-expressing CD25+CD4+ regulatory T cells in self-tolerance and autoimmune disease

Naturally arising CD25+CD4+ regulatory T cells, which express the transcription factor Foxp3, play key roles in the maintenance of immunologic self-tolerance and negative control of a variety of physiological and pathological immune responses. The majority of them are produced by the normal thymus as a functionally mature T cell subpopulation specialized for suppressive function. Their generation is in part genetically and developmentally controlled. Genetically determined or environmentally induced abnormality in CD25+CD4+ regulatory T cell development, maintenance, and function can be a cause of autoimmune disease in humans.

Differential glycosylation of polyclonal IgG, IgG-Fc and IgG-Fab isolated from the sera of patients with ANCA-associated systemic vasculitis

Post-translational modifications (PTMs) of proteins produced in vivo may be tissue, developmentally and/or disease specific. PTMs impact on the stability and function of proteins and offer a challenge to the commercial production of protein biotherapeutics. We have previously reported a marked deficit in galactosylation of oligosaccharides released from polyclonal IgG isolated from sera of patients with the anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitides; Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA). Whilst normal polyclonal IgG molecules are glycosylated within the IgG-Fc region, approximately 20% of molecules also bear oligosaccharides attached to the variable regions of the light or heavy chain IgG-Fab. It is of interest, therefore to compare profiles of oligosaccharides released from the IgG-Fc and IgG-Fab of normal IgG with that isolated from the sera of patients with WG or MPA. This study shows that whilst the oligosaccharides released from ANCA IgG-Fc are hypogalactosylated those released from IgG-Fab are galactosylated and sialylated. These results show that hypogalactosylation of IgG-Fc is not due to a defect in the glycosylation or processing machinery. It rather suggests a subtle change in IgG-Fc conformation that influences the addition of galactose. Remarkably, this influence is exerted on all plasma cells. Interestingly, a licensed monoclonal antibody therapeutic, produced in Sp2/0 cells, is also shown to be hypogalactosylated in its IgG-Fc but fully galactosylated in its IgG-Fab.

Platelets treated with ticlopidine are less reactive to unusually large von Willebrand factor multimers than are those treated with aspirin under high shear stress

Much attention has recently been focused on the interaction between unusually large von Willebrand factor multimers (UL-VWFM) and platelets under high shear stress in pathological thrombus formation. The antiplatelet drugs acetylsalicylic acid (aspirin) and a thienopyridine derivative (ticlopidine) are commonly used to treat cerebral ischemia but exert different effects on high-shear-stress-induced platelet aggregation (H-SIPA) in the plasma. To examine the effects of these drugs in the absence of plasma factors, we studied H-SIPA using washed platelets (WPs) and purified UL-VWFM. WPs were prepared from the blood of 9 aspirin-treated and 11 ticlopidine-treated patients with cerebral ischemia, and H-SIPA in the presence of UL-VWFM was measured using a cone plate aggregometer. Plasma levels of VWF antigen with its multimer analysis, ristocetin cofactor and VWF-cleaving protease (ADAMTS13) activity were also measured. Forty-six healthy volunteers from 2 age groups, 20-40 years (n=20) and 41-60 years old (n=26), were also tested as controls. H-SIPA was significantly inhibited for ticlopidine-treated platelets, but it was observed to a lesser extent for aspirin-treated platelets. For both groups, no difference in the plasma levels of VWF antigen, ristocetin cofactor and ADAMTS13 activity was noted. All patients possessed UL-VWFM, and it was detected in healthy volunteers with increasing frequency with increasing age. Under plasma-free conditions, platelets from aspirin-treated patients exhibit marginal but significant inhibition of H-SIPA. Furthermore, the presence of UL-VWFM in the plasma of patients and normal volunteers is directly related to their age rather than being a consequence of underlying disease.

Thrombotic thrombocytopenic purpura associated with polyarteritis nodosa

We present a case of classical polyarteritis nodosa (PN) overlapping thrombotic thrombocytopenic purpura (TTP). A 70-year-old woman was transferred to our hospital because of general fatigue and fever. On admission, laboratory findings revealed leukocytosis, normochromic normocytic anemia and renal dysfunction. About one week later, she developed disturbance of consciousness, and laboratory findings revealed rapidly progressive thrombocytopenia and renal dysfunction. We suspected the presence of microscopic polyangiitis (MPA), based on mild elevation of myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibody (ANCA). On post-admission Day 11, renal biopsy was performed but the diagnosis of MPA could not be confirmed because of the absence of glomerular crescent formation or vasculitis. However, the biopsy specimen showed many collapsed glomeruli and interstitial inflammation, indicating the presence of occlusive lesions, such as vasculitis in larger arteries. We instituted methylprednisolone pulse therapy, cyclophosphamide and plasma exchange, because the clinical symptoms also satisfied the criteria of TTP. Despite the intensive treatment, the patient died on 43rd day of hospitalization due to thalamic hemorrhage. Autopsy showed typical findings of classical PN including disruption of arterial walls and fibrinoid necrosis in the medium-sized arteries of the kidneys and colon. We detected reduced activity of von Willebrand factor-cleaving protease (VWF-CP) and the presence of plasma inhibitory IgG against VWF-CP. A better understanding of the mechanisms would be useful.

Direct observation of the mass renormalization in SrVO3 by angle resolved photoemission spectroscopy

Band dispersions and Fermi surfaces of the three-dimensional Mott-Hubbard system SrVO3 are directly observed by angle-resolved photoemission spectroscopy. An observed spectral weight distribution near the Fermi level (E(F)) shows cylindrical Fermi surfaces as predicted by band-structure calculations. By comparing the experimental results with calculated surface electronic structures, we conclude that the obtained band dispersion reflects the bulk electronic structure. The enhanced effective electron mass obtained from the energy band near E(F) is consistent with the bulk thermodynamic properties and hence with the normal Fermi-liquid behavior of SrVO3.

Anxiety accelerates T-helper 2-tilted immune responses in patients with atopic dermatitis

BACKGROUND

Stress, which mediates anxiety, worsens skin symptoms in patients with atopic dermatitis (AD). The contribution of anxiety to immune dysfunction, which plays a critical role in the pathogenesis of AD, requires clarification.

OBJECTIVES

To examine the relationship between anxiety and atopy-relevant immune function in AD.

METHODS

Eighty-five patients with AD and 58 normal individuals without a history of allergic disorders were enrolled in this study. To assess anxiety, the state-trait anxiety inventory was completed for both groups. In the AD group, measurements were made of SCORAD scores, serum IgE levels, itching (visual analogue scale), blood eosinophil count and T-helper (Th) 1/Th2 ratio in the peripheral blood.

RESULTS

Anxiety was significantly higher among the subjects with AD than the normal subjects, and trait anxiety (TA) was higher than state anxiety (SA) in the AD group. Serum total IgE levels were correlated positively with TA and the TA/SA ratio and inversely with SA, and the Th1/Th2 ratio was correlated inversely with TA and the TA/SA ratio.

CONCLUSIONS

The patients with AD had higher anxiety levels than normal individuals, and those with a stronger perception of TA than SA showed enhanced serum IgE synthesis and Th2 shifting.

Clinical significance of heparin-binding epidermal growth factor-like growth factor in peritoneal fluid of ovarian cancer

Epidermal growth factor receptor (EGFR) has been implicated in tumour growth and extension of ovarian cancer. Peritoneal fluid in ovarian cancer patients contains various growth factors that can promote tumour growth and extension. In order to investigate the clinical significance of EGFR ligands as activating factors of ovarian cancer, we examined the cell proliferation-promoting activity and the level of EGFR ligands in peritoneal fluid obtained from 99 patients. Proliferation-promoting activity in peritoneal fluid from 63 ovarian cancer patients (OVCA) was much higher than peritoneal fluid from 18 ovarian cyst patients (OVC) and 18 normal ovary patients (NO), and the activity was suppressed only by antibodies against EGFR or heparin-binding epidermal growth factor (HB-EGF). A large difference was observed in the level of EGFR ligands between HB-EGF and TGF-α or amphiregulin. The concentration of HB-EGF in OVCA significantly increased compared to that in OVC or NO (P<0.01). No significant difference in the concentration of TGF-α and amphiregulin was found between the OVCA and NO or OVC groups. In peritoneal fluid, HB-EGF is sufficiently elevated to activate cancer cells even at an early stage of OVCA. These results suggested that HB-EGF in peritoneal fluid might play a key role in cell survival and in the proliferation of OVCA.

Augmentation of transgene expression in cold-preserved organs using vascular endothelial growth factor receptor-mediated adenoviral vector combined with hyperbaric oxygen

Adenovirus-mediated gene transfer has been widely used in gene therapy for congenital metabolic, cardiovascular, and malignant diseases. It has been reported that a gene transfer technique into transplanted organs may suppress rejection reactions and inhibit preservation injury. However, the magnitude of transgene expression in organs preserved at a cold temperature remains to be determined. In this study, we compared the transgene expression using vascular endothelial growth factor receptor (VEGFR)-mediated adenoviral vector at cold versus warm temperatures alone and combined with hyperbaric oxygen in cold-preserved organs. The transgene expression by porcine endothelial cells transduced with adenoviral vector was significantly higher after a 24 hour-incubation at warm temperature than after a 1 hour-incubation with warm or cold temperature. Moreover, the transgene expression of after a 1-hour incubation at cold temperature was significantly lower than a 1-hour incubation at warm temperature. The VEGFR-mediated adenoviral vector augmented transgene expression during a 1-hour incubation at cold temperature compared to the control vector. A/J skin graft survival in C3H mice was significantly prolonged compared to control or standard vector with CTLA4Ig cDNA using VEGFR-mediated adenoviral vector with CTLA4Ig cDNA in a 1-hour cold preservation. Furthermore, combined use of VEGFR-mediated adenoviral vector with CTLA4Ig cDNA plus FK506 showed an augmented effect on graft prolongation. It is concluded that adenovirus-mediated gene transfer in 1-hour cold-preserved organ is difficult compared to that in the warm condition. However, VEGFR-mediated gene transfer can augment the transgene expression in 1-hour cold-preserved organs, followed by the effective suppression of rejection reactions in allogeneic transplantation.

Age-related changes in barrier function in mouse brain I. Accelerated age-related increase of brain transfer of serum albumin in accelerated senescence prone SAM-P/8 mice with deficits in learning and memory

The time course of brain accumulation of radiolabelled human serum albumin ((125)I-HSA) injected intravenously and the transfer of (125)I-HSA from blood to brain were evaluated in DDD mice using a double isotope technique. The brain accumulation of (125)I-HSA at 3 and 9 h but not at 24 h postinjection and the brain transfer rates were significantly higher in 22-month-old DDD mice than in 4-month-old ones. The brain transfer rates of (125)I-HSA were measured also in senescence accelerated prone mice (SAM-P/8) with age-related deficits in learning and memory, and in senescence accelerated resistant mice (SAM-R/I) without these deficits. The brain transfer rates were significantly higher in 13-month-old SAM-P/8 and 22-month-old SAM-R/1 than in 3-month-old mice of the same strains, respectively. The mean brain transfer rates in five regions observed in 22-month-old DDD mice, 22-month-old SAM-R/1 and 13-month-old SAM-P/8 increased by 31%, 41% and 51% compared with corresponding values in 3- or 4-month-old mice of the same strains. DDD mice and SAM-R/1 mice with normal characteristics of aging showed similar age-related significant changes in brain transfer rates. Age-related increase in the brain transfer rate was manifested at the youngest age in SAM-P/8 among the three strains examined. These findings show that the transfer of human serum albumin into the mouse brain increases with aging and suggest that the barrier function in the mouse brain against macromolecules changes with aging.