Summary
Background
The sensitivity of current upper limit of normal (ULN) of serum alanine aminotransferase (ALT) levels for detecting chronic liver disease has been challenged recently.
Aim
To ...identify modulating factors for serum ALT levels and to refine its ULN threshold.
Methods
We enrolled 34 346 consecutive subjects who completed the health check‐up at Taipei Veterans General Hospital from 2002 to 2009. ULN was set for healthy ALT level to the 95th percentile of the reference healthy population.
Results
A group of 21 282 subjects were used as a training set to define an ULN with the highest sensitivity; afterwards, this ULN was validated in another set of 13 064 subjects. A reference healthy population was selected from the training set after excluding subjects with any abnormalities in independent risk factors associated with elevated serum ALT level (>40 IU/L) by multivariate analysis like body mass index, waist circumference, glucose, cholesterol, high‐density lipoprotein‐cholesterol, triglyceride, hepatitis B virus surface antigen, anti‐hepatitis C virus antibody and fatty liver. The new ULN of serum ALT level defined as the 95% percentile in the healthy population were 21 IU/L and 17 IU/L for men and women respectively. These cut‐off values had the highest Youden's index and areas under the corresponding receiver operating curves among four widely applied thresholds in both the training and validation sets.
Conclusions
The suggested threshold of upper limit of normal provides better discrimination between healthy and unhealthy status. Viral hepatitis, metabolic syndrome and fatty liver are the major risk factors of elevated serum alanine aminotransferase levels.
Keratoplasty is the most effective treatment for corneal blindness, but suboptimal medical conditions and lack of qualified medical personnel and donated cornea often prevent the performance of ...corneal transplantation in developing countries. Our study aims to develop alternative treatment regimens for congenital corneal diseases of genetic mutation.
Human mesenchymal stem cells isolated from neonatal umbilical cords were transplanted to treat thin and cloudy corneas of lumican null mice. Transplantation of umbilical mesenchymal stem cells significantly improved corneal transparency and increased stromal thickness of lumican null mice, but human umbilical hematopoietic stem cells failed to do the same. Further studies revealed that collagen lamellae were re-organized in corneal stroma of lumican null mice after mesenchymal stem cell transplantation. Transplanted umbilical mesenchymal stem cells survived in the mouse corneal stroma for more than 3 months with little or no graft rejection. In addition, these cells assumed a keratocyte phenotype, e.g., dendritic morphology, quiescence, expression of keratocyte unique keratan sulfated keratocan and lumican, and CD34. Moreover, umbilical mesenchymal stem cell transplantation improved host keratocyte functions, which was verified by enhanced expression of keratocan and aldehyde dehydrogenase class 3A1 in lumican null mice.
Umbilical mesenchymal stem cell transplantation is a promising treatment for congenital corneal diseases involving keratocyte dysfunction. Unlike donated corneas, umbilical mesenchymal stem cells are easily isolated, expanded, stored, and can be quickly recovered from liquid nitrogen when a patient is in urgent need.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Mucopolysaccharidosis (MPS) are a family of related disorders caused by a mutation in one of the lysosomal exoglycosidases which leads to the accumulation of glycosaminoglycans (GAGs). MPS VII, ...caused by a mutation in β‐glucuronidase, manifests hepatomegaly, skeletal dysplasia, short stature, corneal clouding, and developmental delay. Current treatment regimens for MPS are not effective for treating corneal clouding and impaired mental development. We hypothesized that human umbilical mesenchymal stem cells (UMSCs) transplanted into the corneal stroma could participate in the catabolism of GAGs providing a means of cell therapy for MPS. For such treatment, human UMSCs were intrastromally transplanted into corneas of MPS VII mice. UMSC transplantation restored the dendritic and hexagonal morphology of host keratocytes and endothelial cells, respectively, and in vivo confocal microscopy (HRT‐II) revealed reduced corneal haze. Immunohistochemistry using antibodies against heparan sulfate and chondroitin sulfate chains as well as lysosomal‐associated membrane protein 2 revealed a decrease in GAG content and both lysosomal number and size in the treated corneas. Labeling UMSC intracellular compartments prior to transplantation revealed the distribution of UMSC vesicles throughout the corneal stroma and endothelium. An in vitro coculture assay between skin fibroblasts isolated from MPS VII mice and UMSC demonstrated that neutral vesicles released by the UMSC are taken up by the fibroblasts and proceed to fuse with the acidic lysosomes. Therefore, transplanted UMSCs participate both in extracellular GAG turnover and enable host keratocytes to catabolize accumulated GAG products, suggesting that UMSC could be a novel alternative for treating corneal defects associated with MPS and other congenital metabolic disorders. Stem Cells 2013;31:2116–2126
The reactions between Cu and the Sn2.5Ag0.8Cu solders doped with 0.03
wt.% Fe, Co, or Ni were studied. Reaction conditions included multiple reflows for up to 10 times and solid-state aging at 160
°C ...for up to 2000
h. In the multiple reflow study, Cu
6Sn
5 was the only reaction product noted for all the different solders used. Reflows using the solder without doping produced a thin, dense layer of Cu
6Sn
5. Adding Fe, Co, or Ni transformed this microstructure into a much thicker Cu
6Sn
5 with many small trapped solder regions between the Cu
6Sn
5 grains. In the solid-state aging study, both Cu
6Sn
5 and Cu
3Sn formed, but adding Fe, Co, or Ni produced a much thinner Cu
3Sn layer. Because the Cu
3Sn growth had been linked to the formation of micro voids, which in turn increased the potential for a brittle interfacial fracture, thinner Cu
3Sn layers might translate into better solder joint strength.
Mesenchymal stem cells isolated from connective tissues are pluripotent and differentiate into phenotypes of connective tissue cell lineages (osteoblasts, chondrocytes, and adipocytes) in vitro and ...in vivo. They have been used to treat mouse models of connective tissue disease such as lumican-null (Lum) and mucopolysaccharidosis (Gusb) mice. Mesenchymal stem cells have unique immunosuppressive properties allowing evasion of host rejection; thus, they are valuable tools for cell therapy of congenital and acquired diseases involving immune dysfunction of multiple tissues including ocular surface tissues (cornea). We previously showed that human umbilical mesenchymal stem cells (UMSCs) modulated host immune responses, enabling them to survive xenograft transplantation. In vitro, UMSCs modulated inflammatory cells by inhibiting adhesion and invasion, and inducing cell death. UMSCs also regulated M1/M2 macrophage polarization and induced T-regulatory cell maturation from naive intraperitoneal cavity lavage cells. UMSCs exposed to inflammatory cells synthesized a rich extracellular glycocalyx composed of hyaluronan (HA) bound to the heavy chains (HCs) of inter-alpha-trypsin inhibitor (HC-HA), which contains tumor necrosis factor-α-stimulated gene 6 (TSG6) that catalyzes the transfer of HCs to HA, versican, and pentraxin-3. Our in vivo and in vitro results showed that the glycocalyx regulated inflammatory cells, allowing UMSCs to survive host immune rejection. Administration of antibodies against glycocalyx constituents or digestion with hyaluronidase and chondroitinase ABC abolished the UMSCsʼ ability to modulate immune responses. Treatment with anti-CD44 antibodies also diminished modulation of M2 macrophages by UMSCs, indicating that cell surface CD44 is required for correct UMSC glycocalyx assembly to modulate inflammatory cells.
Corneal scarring from trauma and inflammation disrupts vision for millions worldwide, but corneal transplantation, the primary therapy for corneal blindness, is unavailable to many affected ...individuals. In this study, stem cells isolated from adult human corneal stroma were examined for the ability to correct stromal opacity in a murine model by direct injection of cells into the corneal stroma. In wild‐type mice, injected human stem cells remained viable for months without fusing with host cells or eliciting an immune T‐cell response. Human corneal‐specific extracellular matrix, including the proteoglycans lumican and keratocan, accumulated in the treated corneas. Lumican‐null mice have corneal opacity similar to that of scar tissue as a result of disruption of stromal collagen organization. After injection with human stromal stem cells, stromal thickness and collagen fibril defects in these mice were restored to that of normal mice. Corneal transparency in the treated mice was indistinguishable from that of wild‐type mice. These results support the immune privilege of adult stem cells and the ability of stem cell therapy to regenerate tissue in a manner analogous to organogenesis and clearly different from that of normal wound healing. The results suggest that cell‐based therapy can be an effective approach to treatment of human corneal blindness. STEM CELLS 2009;27:1635–1642
Pseudoexfoliation (PEX) syndrome is an age-related systemic disease with ocular manifestations. The development of animal models is critical in order to elucidate the cause of the disease and to test ...potential treatment regimens. The purpose of this study is to report phenotypes found in mouse eyes injected with Adenovirus coding Wnt5a. Some of the phenotypes resemble those found in PEX patients while others are different.
Recombinant Adenovirus coding Wnt5a or green fluorescent protein (GFP) were injected into mouse eyes. Two months after the injection, eyes were examined for PEX phenotypes using slit lamp, fluorescence stereomicroscope, histological staining, immunostaining and transmission electron microscope.
Certain ocular features of PEX syndrome were found in mouse eyes injected with recombinant Adenovirus coding Wnt5a. These features include accumulation of exfoliation-like extracellular material on surfaces of anterior segment structures and its dispersion in the anterior chamber, saw-tooth appearance and disrupted basement membrane of the posterior iris pigment epithelium, iris stromal atrophy and disorganized ciliary zonules. Ultrastructure analysis of the exfoliation material revealed that the microfibril structure found in this model was different from those of PEX patients.
These features, resembling signs of ocular PEX syndrome in patients, suggest that new information obtained from this study will be helpful for developing better mouse models for PEX syndrome.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To evaluate the possible association between paediatric head computed tomography (CT) examination and increased subsequent risk of malignancy and benign brain tumour.
In the exposed cohort, 24 418 ...participants under 18 years of age, who underwent head CT examination between 1998 and 2006, were identified from the Taiwan National Health Insurance Research Database (NHIRD). Patients were followed up until a diagnosis of malignant disease or benign brain tumour, withdrawal from the National Health Insurance (NHI) system, or at the end of 2008.
The overall risk was not significantly different in the two cohorts (incidence rate=36.72 per 100 000 person-years in the exposed cohort, 28.48 per 100 000 person-years in the unexposed cohort, hazard ratio (HR)=1.29, 95% confidence interval (CI)=0.90-1.85). The risk of benign brain tumour was significantly higher in the exposed cohort than in the unexposed cohort (HR=2.97, 95% CI=1.49-5.93). The frequency of CT examination showed strong correlation with the subsequent overall risk of malignancy and benign brain tumour.
We found that paediatric head CT examination was associated with an increased incidence of benign brain tumour. A large-scale study with longer follow-up is necessary to confirm this result.
The main goal of this paper is to provide insights into swash flow dynamics, generated by a non-breaking solitary wave on a steep slope. Both laboratory experiments and numerical simulations are ...conducted to investigate the details of runup and rundown processes. Special attention is given to the evolution of the bottom boundary layer over the slope in terms of flow separation, vortex formation and the development of a hydraulic jump during the rundown phase. Laboratory experiments were performed to measure the flow velocity fields by means of high-speed particle image velocimetry (HSPIV). Detailed pathline patterns of the swash flows and free-surface profiles were also visualized. Highly resolved computational fluid dynamics (CFD) simulations were carried out. Numerical results are compared with laboratory measurements with a focus on the velocities inside the boundary layer. The overall agreement is excellent during the initial stage of the runup process. However, discrepancies in the model/data comparison grow as time advances because the numerical model does not simulate the shoreline dynamics accurately. Introducing small temporal and spatial shifts in the comparison yields adequate agreement during the entire rundown process. Highly resolved numerical solutions are used to study physical variables that are not measured in laboratory experiments (e.g. pressure field and bottom shear stress). It is shown that the main mechanism for vortex shedding is correlated with the large pressure gradient along the slope as the rundown flow transitions from supercritical to subcritical, under the developing hydraulic jump. Furthermore, the bottom shear stress analysis indicates that the largest values occur at the shoreline and that the relatively large bottom shear stress also takes place within the supercritical flow region, being associated with the backwash vortex system rather than the plunging wave. It is clearly demonstrated that the combination of laboratory observations and numerical simulations have indeed provided significant insights into the swash flow processes.
It remains elusive as to what bone marrow (BM) cell types infiltrate into injured and/or diseased tissues and subsequently differentiate to assume the phenotype of residential cells, for example, ...neurons, cardiac myocytes, keratocytes, etc., to repair damaged tissue. Here, we examined the possibility of whether BM cell invasion via circulation into uninjured and injured corneas could assume a keratocyte phenotype, using chimeric mice generated by transplantation of enhanced green fluorescent protein (EGFP)+ BM cells into keratocan null (Kera−/−) and lumican null (Lum−/−) mice. EGFP+ BM cells assumed dendritic cell morphology, but failed to synthesize corneal‐specific keratan sulfate proteoglycans, that is KS‐lumican and KS‐keratocan. In contrast, some EGFP+ BM cells introduced by intrastromal transplantation assumed keratocyte phenotypes. Furthermore, BM cells were isolated from Kera‐Cre/ZEG mice, a double transgenic mouse line in which cells expressing keratocan become EGFP+ due to the synthesis of Cre driven by keratocan promoter. Three days after corneal and conjunctival transplantations of such BM cells into Kera−/− mice, green keratocan positive cells were found in the cornea, but not in conjunctiva. It is worthy to note that transplanted BM cells were rejected in 4 weeks. MSC isolated from BM were used to examine if BM mesenchymal stem cells (BM‐MSC) could assume keratocyte phenotype. When BM‐MSC were intrastromal‐transplanted into Kera−/− mice, they survived in the cornea without any immune and inflammatory responses and expressed keratocan in Kera−/− mice. These observations suggest that corneal intrastromal transplantation of BM‐MSC may be an effective treatment regimen for corneal diseases involving dysfunction of keratocytes.
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