P42 Ebp1 regulates the proteasomal degradation of the p85 regulatory subunit of PI3K by recruiting a chaperone-E3 ligase complex HSP70/CHIP.

The short isoform of ErbB3-binding protein 1 (Ebp1), p42, is considered to be a potent tumor suppressor in a number of human cancers, although the mechanism by which it exerts this tumor-suppressive activity is unclear. Here, we report that p42 interacts with the cSH2 domain of the p85 subunit of phosphathidyl inositol 3-kinase (PI3K), leading to inhibition of its lipid kinase activity. Importantly, we found that p42 induces protein degradation of the p85 subunit and further identified HSP70/CHIP complex as a novel E3 ligase for p85 that is responsible for p85 ubiquitination and degradation. In this process, p42 couples p85 to the HSP70/CHIP-mediated ubiquitin-proteasomal system (UPS), thereby promoting a reduction of p85 levels both in vitro and in vivo. Thus, the tumor-suppressing effects of p42 in cancer cells are driven by negative regulation of the p85 subunit of PI3K.

An epidemiological study of androgenic alopecia in 3114 Korean patients.

BACKGROUND: Androgenetic alopecia (AGA) is the most common type of hair loss, and is characterized by the transformation of terminal scalp hair into vellus hair. The epidemiology of AGA is not fully understood. A strong genetic basis has long been identified, although little is known of its nongenetic causes. AIM: To evaluate the association of AGA with a number of environmental factors, including smoking, drinking and sleeping habit. METHODS: In total, 3114 Korean individuals with AGA who attended any one of 17 dermatology clinics in 6 cities in South Korea between March 2011 and February 2012 were enrolled in the study. Epidemiologic a data were collected using a standard questionnaire. RESULTS: No association was seen between eating or sleeping habits and severity of hair loss. However, drinking and smoking were associated with the severity of AGA in male patients. We also found that patients of both genders with a family history had more advanced types of hair loss, and the age of onset of AGA in male patients with a family history was earlier than that in male patients without a family history. CONCLUSIONS: Although the evidence for an environmental influence on AGA remains very weak, we did find an association between hair loss severity and certain environmental factors, such as smoking and drinking. Family history with more severe hair loss and an earlier age of onset.

Association of a microRNA-323b polymorphism with the persistence of hepatitis B virus infection by the enhancement of viral replication.

Recent studies have shown that some mammalian microRNAs (miRNAs) play a role in antiviral defence. However, little is known about the role of miRNA-323b in hepatitis B virus (HBV)-host interaction. We explored whether single nucleotide polymorphism (SNP) of miRNA-323b affects HBV replication in a Korean HBV cohort. Genotyping was performed in a total of 1439 subjects composed of 404 spontaneously recovered (SR) subjects as normal controls and 1035 chronic carriers (CC) of HBV who were further classified into 313 patients with chronic hepatitis, 305 patients with liver cirrhosis and 417 patients with hepatocellular carcinoma. To confirm the effect of SNP of miRNA-323b on HBV replication in vitro, HepAD38 cells were transfected with miRNA-323b wild type or miRNA-323b SNP plasmid vectors, and HBV replication was induced for 5 days. HBV DNA was isolated and quantified using real-time PCR. The polymorphism rs56103835C>T in the pre-miRNA region of miRNA-323b revealed significant minor allele frequency (0.273). rs56103835C>T SNP showed significantly affect persistence of HBV in CC group compared with SR group (OR = 1.29, P = 0.009 in a codominant model; OR = 1.29, P = 0.03 in a dominant model; and OR = 1.78, P = 0.03 in a recessive model). In vitro, the total intracellular HBV DNA content was significantly reduced by miRNA-323b wild-type plasmid vector transfection (P = 0.014). The polymorphism of miRNA-323b was significantly associated with persistence of HBV by the enhancement of HBV replication (P = 0.021). Our findings provide a novel perspective on the role SNP of miRNAs in host-virus interactions in HBV infection.

Computer-navigated total knee arthroplasty in haemophilic arthropathy.

Total knee arthroplasty (TKA) in end-stage haemophilic arthropathy is complex and challenging due to the altered bony anatomy, arthrofibrosis and muscle contractures. Computer navigation is especially advocated in patients with deformity or altered anatomy to improve alignment and to assist in ligament balancing. The objective of this study was to evaluate the results of computer-navigated TKA in haemophilic arthropathy. A consecutive series of computer-assisted TKA for the end-stage haemophilic arthropathy between February 2007 and December 2009 were evaluated. A total of 27 TKA were performed in 25 patients. Pre- and postoperative full-length weight-bearing radiographs were assessed for the axial limb alignment. The orientation of the components was measured on anteroposterior radiographs. Clinically, Knee Society score and Short Form-36 were evaluated. The mechanical axis of the leg was within a range of ±3° varus/valgus in 92% of the TKA. The coronal alignment of the femoral and tibial components was within a range of ±3 degrees in 96% of the knees. The clinical outcomes were significantly improved after the operation. There were no complications specific to the computer navigation. Computer-navigated TKA helps in restoring the mechanical axis and improves accuracy of orientation of the components in patients with end-stage haemophilic arthropathy. Potential benefits in long-term outcome require further investigation.

Intravitreal bevacizumab and ranibizumab injections for patients with polypoidal choroidal vasculopathy.

PURPOSE: To compare the effectiveness of intravitreal injection of bevacizumab and ranibizumab in patients with treatment-naïve polypoidal choroidal vasculopathy (PCV). METHODS: A total of 66 and 60 eyes of 121 consecutive patients who received intravitreal bevacizumab (1.25 mg) or ranibizumab (0.5 mg) injection for treatment of PCV were retrospectively reviewed. After initial three loading injections by month, injection was performed as needed. Main outcome measures included best corrected visual acuity (BCVA), foveal center thickness (FCT) as assessed by spectral domain optical coherence tomography (SD-OCT), and change in polypoidal lesion on indocyanine green angiography (ICGA). RESULTS: At 12 months, average number of injections was 4.72±1.84 in the bevacizumab group and 5.52±1.54 in the ranibizumab group. Mean logarithm of the minimum angle of resolution of BCVA from baseline at 12 months after injection improved by 0.11 in the bevacizumab group (P=0.02) and by 0.14 in the ranibizumab group (P=0.01). Average FCT decreased from 368±62.48 to 298±40.77 µm in the bevacizumab group (P=0.01) and from 371±50.79 to 286±36.93 µm in the ranibizumab group (P=0.01). Polyp regression rate was 24.2% (16 eyes out of 66 eyes) in the bevacizumab group and 23.3% (14 eyes out of 60 eyes) in the ranibizumab group. There was no statistically significant difference in BCVA improvement achieved, FCT improvement achieved, and polyp regression rate between groups. CONCLUSION: Intravitreal injections of bevacizumab and ranibizumab have similar effects in stabilization of visual acuity, macular edema, and regression of polypoidal complex with PCV eyes.

Safety of liver resection in the elderly: how important is age?

BACKGROUND: With the aging population, more elderly patients are being considered for hepatic resection. We investigated whether advanced age was associated with higher rate and severity of postoperative complications. METHODS: A total of 75 patients aged ≥70 years (group E) were matched with 75 patients aged <70 years (group Y) by the extent of liver resection and by operative indications. Primary outcome measures were rates and severity of complications. Secondary outcome measures were length of hospital stay and discharge destination. Univariate analysis was also performed to identify variables associated with higher surgical risk. RESULTS: Male-to-female ratio was 43:32 in both groups. Overall complication rates were 44 and 33.3% in group E and Y, respectively (P = 0.241; odds ratio = 1.57; 95% confidence interval [95% CI], 0.81-3.05). There was no mortality in both groups. The only postoperative age-related morbidity was confusion in the elderly. There was no difference in the rates of severe complications (grade ≥3) between group E and group Y (16 vs. 14.7%; P = 0.744; odds ratio = 1.11; 95% CI, 0.46-2.70). Median length of hospital stay were 7 and 6 days, respectively (P = 0.01). Nineteen percent and 1% of patients in group E and group Y were discharge to rehabilitation facilities, respectively (P = 0.001). Univariate analysis showed that preoperative systemic chemotherapy and longer operative time were associated with higher morbidity in the elderly. CONCLUSIONS: Liver resection can be performed in patients aged ≥70 years as safely as in younger patients. Duration and timing of systemic chemotherapy before liver resection should be optimized to minimize postoperative morbidity.

Factors that affect the diagnostic accuracy of liver fibrosis measurement by Fibroscan in patients with chronic hepatitis B.

BACKGROUND: Interquartile range/median value (IQR/M) of liver stiffness measurement (LSM) is a factor in chronic hepatitis C (CHC) leading to over estimation of fibrosis by Fibroscan. AIM: To investigate factors that affect the accuracy of LSM in chronic hepatitis B (CHB). METHODS: One hundred and ninety-nine patients were enrolled. Only procedures yielding > or =10 valid measurements were considered reliable. Liver fibrosis was evaluated using the Batts and Ludwig system. Liver biopsy (LB) specimens <15 mm were considered ineligible. RESULTS: The mean age (142 men and 57 women) was 40.1 years. A significant discordance (discordance of at least two stages between LB and LSM) was identified in 38 (19.1%) and 47 (23.6%) patients respectively, according to Marcellin et al. and Chan et al.'s cutoff values. In multivariate analyses, BMI and fibrosis stage (F0-2 vs. F3-4) were identified as independent predictors for significant discordance (P = 0.040; hazard ratio [HR], 1.126; 95% confidence interval [CI], 1.005-1.261 and P = 0.036; HR, 0.450; 95% CI, 0.213-0.949 respectively) with Marcellin et al.'s cutoffs, whereas fibrosis stage was the only independent predictor (P = 0.004; HR, 0.300; 95% CI, 0.131-0.685) with Chan's cutoffs. CONCLUSIONS: Success rate and IQR/M were not predictive factors of the accuracy for diagnosing liver fibrosis by Fibroscan in CHB. Fibrosis stage (F0-2) was the only factor to predict significant discordance between LB and LSM.

Electronic structure of N,N'-ethylene-bis(1,1,1-trifluoropentane-2,4-dioneiminato)-copper(II) (Cu-TFAC), from soft X-ray spectroscopies and density functional theory calculations.

The element and orbital-specific electronic structure of thin films of the organic material N,N'-ethylene-bis(1,1,1-trifluoropentane-2,4-dioneiminato)-copper(II) (designated as Cu-TFAC) has been studied using a combination of synchrotron radiation-excited resonant X-ray emission spectroscopy, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and density functional theory calculations. Furthermore, resonant X-ray emission at the carbon K-edge was used to measure the density of states for individual C sites in the molecule.

Gene delivery to human adult and embryonic cell-derived stem cells using biodegradable nanoparticulate polymeric vectors.

Gene delivery to stem cells holds great potential for tissue regeneration and delivery of therapeutic proteins. The major barrier is the lack of safe and efficient delivery methods. Here, we report enhanced gene delivery systems for human stem cells using biodegradable polymeric vectors. A library of poly (beta-amino esters) end-modified derivatives was developed and optimized for high transfection efficiency and low cytotoxicity for three human stem cell lines including human mesenchymal stem cells (hMSCs), human adipose-derived stem cells (hADSCs) and human embryonic stem cell-derived cells (hESCds). In the presence of 10% serum, leading end-modified C32 polymeric vectors exhibited significantly high transfection efficiency in hMSCs (27+/-2%), hADSCs (24+/-3%) and hESCds (56+/-11%), with high cell viability (87-97%) achieved in all cell types. Our results show that poly(beta-amino esters) as a class, and end-modified versions of C32 in particular, are efficient polymeric vectors for gene delivery to both adult and embryonic-derived stem cells.

Genetic association between functional haplotype of collagen type III alpha 1 and chronic hepatitis B and cirrhosis in Koreans.

Collagen type III alpha 1 (COL3A1) is one of the extracelluar matrix (ECM) proteins. The expression of COL3A1 is closely related to chronic liver diseases. In this study, we investigated whether single nucleotide polymorphisms (SNPs) of COL3A1 confer genetic susceptibility to patients with hepatitis B virus-infected liver diseases including chronic hepatitis B (CH), liver cirrhosis (CIR), and hepatocellular carcinoma (HCC). A total of 399 Korean (KOR) people, 111 patients with CH, 95 patients with CIR, 86 patients with HCC, and 107 spontaneously recovery, were genotyped for 16 SNPs of the COL3A1 gene. The 'A' allele of rs3106796 was highly associated with the CH [odds ratio (OR) = 1.62, P = 0.01], CIR (OR = 1.67, P = 0.01), and HCC (OR = 1.59, P = 0.03). There were six polymorphic SNPs that could be divided into two linkage disequilibrium (LD) blocks. The haplotype pattern of the KOR control seems to be similar to the patterns displayed in the Japanese, Chinese, and Caucasian populations sampled in the International HapMap project. Haplotype 3 (A-G-A) of the LD block 2 was significantly associated with CH (OR = 2.23, P = 0.02), CIR (OR = 2.24, P = 0.03), and HCC (OR = 2.27, P = 0.03). Moreover, diplotype analysis showed that they had increased relative risk for CH and CIR in the two diplotypes, dt3 (A-G-A/G-G-A; OR = 4.05, P = 0.01) and dt6 (A-A-A/A-G-A; OR = 7.42, P = 0.01 and OR = 5.84, P = 0.05) against dt1 (G-G-A/G-G-A), the most common diplotype in both KOR groups. In vitro reporter gene assays showed that the constructs containing the 'G' allele of rs3106796 appear to exert lower transcriptional activity of COL3A1 than the 'A' allele, depending on the promoter types.

Surgical management of leiomyosarcoma of the inferior vena cava.

INTRODUCTION: Leiomyosarcoma of the inferior vena cava (IVC) is a rare tumor for which en bloc resection offers the only chance of cure. Due to its rarity, however, optimal strategies for the management of the primary tumor and subsequent recurrences are not well defined. METHODS: We performed a retrospective review of patients who underwent surgical resection of IVC leiomyosarcoma. We evaluated clinical presentations, operative techniques, patterns of recurrence and survival. RESULTS: From 1990 to 2008, nine patients (four females) were identified. Median age was 55 years (40-76). Presentations included abdominal pain (n = 5), back pain (n = 2), leg swelling (n = 4) and abdominal mass (n = 2). Pre-operative imaging studies showed tumor location to be from the right atrium to renal veins (n = 1), retrohepatic (n = 5), and from hepatic veins to the iliac bifurcations (n = 3). En bloc resection included right nephrectomy (n = 5), right adrenalectomy (n = 4), pancreaticoduodenectomy (n = 1), right hepatic trisectionectomy (n = 1) and right hemicolectomy (n = 1). The IVC was ligated in six patients, and a prosthetic graft was used for IVC reconstruction in three patients. Resection margins were negative in seven cases. Median length of stay was 12 days (range, 6-22 days). Major morbidity included renal failure (n = 1) and there was one post-operative mortality. Five patients had leg edema post-operatively, four of whom had IVC ligation. Median survival was 47 months (range, 1-181 months). Four patients had recurrence and the median time to recurrence was 14 months (range, 3-25 months). Two patients underwent successful resection of recurrence. CONCLUSIONS: Curative resection of IVC leiomyosarcoma can lead to long-term survival. However, recurrence is common, and effective adjuvant treatments are needed. In selected cases, aggressive surgical treatment of recurrence should be considered.

Alteration of BMP-4 and Runx2 expression patterns in mouse temporomandibular joint after ovariectomy.

OBJECTIVE: Temporomandibular disorder (TMD) includes a number of clinical conditions involving the masticatory musculature or the temporomandibular joint (TMJ) and associated structures. Previous studies have shown the presence of high-affinity estrogen receptors in the TMJ articular cartilage. The aim of this study was to evaluate the developmental changes in mouse TMJ under estrogen deficiency. MATERIALS AND METHODS: Four-month-old ovariectomized mice were killed after certain weeks. We examined the significant alterations of the expression patterns of bone morphogenetic protein (BMP)-4, Runx2, and bone sialoprotein (BSP) after ovariectomy. RESULTS: In the control group, BMP-4, Runx2, and BSP expressions showed no definite difference at any stage. In the ovariectomy group, the intensity of BMP-4 and Runx2 expression increased after ovariectomy. BSP immunoreactivity, however, increased slightly at 2 weeks but then decreased gradually. CONCLUSIONS: Estrogen plays important roles in the metabolism and maintenance of TMJ via regulations of signaling molecules such as BMP-4, Runx2, and BSP. Our results suggest that estrogen deficiency is a candidate cause of TMD. This study revealed further osteogenetic properties of estrogen that may be useful in the clinical treatment and prevention of TMD.

Inhibition of apoptosis in early tooth development alters tooth shape and size.

Apoptosis plays important roles in various stages of organogenesis. In this study, we hypothesized that apoptosis would play an important role in tooth morphogenesis. We examined the role of apoptosis in early tooth development by using a caspase inhibitor, z-VAD-fmk, concomitant with in vitro organ culture and tooth germ transplantation into the kidney capsule. Inhibition of apoptosis at the early cap stage did not disrupt the cell proliferation level when compared with controls. However, the macroscopic morphology of mice molar teeth exhibited dramatic alterations after the inhibition of apoptosis. Crown height was reduced, and mesiodistal diameter was increased in a concentration-dependent manner with z-VAD-fmk treatment. Overall, apoptosis in the enamel knot would be necessary for the proper formation of molar teeth, including appropriate shape and size.

Novel action of gastric proton pump inhibitor on suppression of Helicobacter pylori induced angiogenesis.

BACKGROUND: Although activation of mitogen activated protein kinases (MAPKs) by Helicobacter pylori infection is associated with induction of host angiogenesis, which may contribute to H pylori associated gastric carcinogenesis, the strategy for its prevention has not been identified. As we previously reported a strong inhibitory action of gastric proton pump inhibitors (PPIs) on MAPK extracellular signal regulated kinase (ERK)1/2 phosphorylation, we investigated whether PPIs could suppress the H pylori induced angiogenesis via inhibition of MAPK ERK1/2. METHODS: To address the relationship between H pylori infection and angiogenesis, comparative analysis of density of CD34(+) blood vessel was performed in tissues obtained from 20 H pylori positive gastritis and 18 H pylori negative gastritis patients. Expression of hypoxia inducible factor 1 (HIF-1alpha) and vascular endothelial growth factor (VEGF) was tested by reverse transcription-polymerase chain reaction and secretion of interleukin 8, and VEGF was measured by ELISA. To evaluate the direct effect of H pylori infection on the tubular formation of human umbilical vein endothelial cells (HUVEC), an in vitro angiogenesis assay was employed. Activation of MAPK and nuclear factor kappaB (NFkappaB) was detected by immunoblotting. RESULTS: H pylori positive gastritis patients showed a higher density of CD34(+) blood vessels (mean 40.9 (SEM 4.4)) than H pylori negative gastritis patients (7.2+/-0.8), which was well correlated with expression of HIF-1alpha. Conditioned media from H pylori infected gastric epithelial cells directly induced tubular formation of HUVEC and the increase of in vitro angiogenesis was suppressed by PPI treatment. Infection of H pylori significantly upregulated expression of HIF-1alpha and VEGF in gastric epithelial cells and expression of proangiogenic factors was mediated by MAPK activation and partially responsible for NFkappaB activation. PPIs effectively inhibited the phosphorylation of MAPK ERK1/2 that is a principal signal for H pylori induced angiogenesis. CONCLUSIONS: The fact that PPIs could downregulate H pylori induced angiogenesis indicates that antiangiogenic treatment using a PPI could be a promising protective therapeutic approach for H pylori associated carcinogenesis.

Inactivation of human glutamate dehydrogenase by aluminum.

Aluminum inactivated glutamate dehydrogenase (GDH) by a pseudo-first-order reaction at micromolar concentrations. A double-reciprocal plot gave a straight line with a k(inact) of 2.7 min(-1) and indicated the presence of a binding step prior to inactivation. The inactivation was strictly pH dependent and a marked increase in sensitivity to aluminum was observed as the pH decreased. At a pH higher than 8.5, no inactivation was observed. The completely inactivated GDH contained 2 mol of aluminum per mole of enzyme subunit monomer. When preincubated with enzyme, several chelators such as citrate, NaF, N-(2-hydroxyethyl) ethylenediaminetriacetic acid or ethylenediaminetriacetic acid efficiently protected the enzyme against the aluminum inactivation. In a related experiment, only citrate and NaF released the aluminum from the completely inactivated aluminum-enzyme complex and fully recovered the enzyme activity. Ferritin, NADP+, or nerve growth factor did not show any effects on the recovery of the aluminum-inactivated GDH activity. The dissociation constant for the aluminum-enzyme complex was calculated to be 5.3 microM. Although aluminum has been known to form a complex with nucleotides, no such effects were observed in the inactivation of GDH by aluminum as determined using GDHs mutated at the ADP-binding site, NAD+-binding site or GTP-binding site. Circular dichroism studies showed that the binding of aluminum to the enzyme induced a decrease in alpha helices and beta sheets and an increase in random coil. Therefore, inactivation of GDH by aluminum is suggested to be due to the conformational change induced by aluminum binding. These results suggest a possibility that aluminum-induced alterations in enzymes of the glutamate system may be one of the causes of aluminum-induced neurotoxicity.

Long-term evaluation of mice model infected with Helicobacter pylori: focus on gastric pathology including gastric cancer.

BACKGROUND: Long-term evaluation of gastric pathology after H. pylori infection is very important in order to reveal its clinical implications, since debate still exists on the gastric carcinogenesis provoked by H. pylori infection in animal models. AIM: Either to evaluate the long-term outcome of H. pylori infection or to determine how H. pylori could provoke gastric cancer in the mice model. METHODS: Four-week-old specific pathogen free C57BL/6 mice (n = 115) were infected with SS1, the mouse-adapted H. pylori strain. After 4, 8, 16, 24, 36, 50 and 80 weeks of bacterial infection, the H. pylori-infected mice were sacrificed. RESULTS: After 80 weeks of infection, almost all the H. pylori-infected mice developed hyperplastic gastritis, but did not show any evidence of gastric adenoma, dysplasia or carcinoma. PCNA positive cells were most abundant after 50 weeks and tended to decrease thereafter up to 80 weeks, whereas apoptosis began to be noted 8 weeks after H. pylori infection, showing 7-8 apoptotic cells/high power field, and tending to increase as time passed. Normally observed neutral mucin decreased during the experiment, showing the most marked decrease 50 weeks after H. pylori infection. In contrast, acidic mucin was noted from 50 weeks after infection. CONCLUSION: The SS1-infected mouse seems to be a suitable animal model for H. pylori-related research, and H. pylori itself does not induce gastric cancer in normal wild-type mouse model following long-term exposure, which could be explained by the balance that exists between cell proliferation and apoptosis.

Effect of long-term administration of rebamipide on Helicobacter pylori infection in mice.

BACKGROUND: It has been suggested that chronic, persistent, uncontrolled inflammations in the stomach could provide the basic step for the beginning of carcinogenesis. One of the potential clinical applications of rebamipide is the inhibition of the immunoinflammatory response in gastric mucosa imposed by Helicobacter pylori. AIM: To determine the implications of long-term rebamipide treatment in H. pylori infection, we studied the underlying moleculo-pathological changes in gastric lesions in mice infected with H. pylori (SS1 strain), following this treatment. METHODS: C57BL/6 mice were sacrificed 24 and 50 weeks after H. pylori infection, respectively. Colonization rates of H. pylori, degree of gastric inflammation and other pathological changes including atrophic gastritis and metaplasia, serum levels of IL-1beta, TNF-alpha, IFN-gamma and IL-10, mRNA transcripts of various mouse cytokines and chemokines, and NF-kappaB binding activities, and finally the presence of gastric adenocarcinoma were compared between an H. pylori infected group (HP), and an H. pylori infected group administered with long-term rebamipide-containing pellet diets (HPR). RESULTS: Serum levels of IL-1beta, IFN-gamma and TNF-alpha, the gastric mucosal expression of ICAM-1, HCAM and MMP, and transcriptional regulation of NF-kappaB-DNA binding were all significantly decreased in the HPR group compared with the HP group. An RNase protection assay showed, in the rebamipide administered group, significantly decreased mRNA levels of apoptosis-related genes such as caspase-8, FasL, Fas, TRAIL and various cytokines genes such as IFN-gamma, RANTES, TNF-alpha, TNFR p75, IL-1beta. In the experiment designed to provoke gastric cancer through MNU treatment with H. pylori infection, the incidence of gastric carcinoma was not different in either group. However, long-term administration of rebamipide showed the advantage of decreasing precancerous lesions like chronic atrophic gastritis and showed molecular evidence of attenuation of proliferation. CONCLUSION: The long-term administration of rebamipide should be considered in the treatment of H. pylori since it demonstrated molecular and biological advantages like a lessening of gastric inflammation and a possible chemopreventive effect.

Pictorial review: various causes of hepatic capsular retraction: CT and MR findings.

Hepatic capsular retraction adjacent to hepatic tumour is rare, although this finding has been described in a variety of malignant tumours and haemangioma. The authors have seen various causes of hepatic capsular retraction associated with hepatic tumours, including a variety of malignant tumours, haemangioma and post-treatment of malignant tumours, as well as cases not associated with a hepatic tumour, including confluent hepatic fibrosis, oriental cholangiohepatitis and bile duct necrosis. Furthermore, causes of pseudoretraction of the hepatic capsule, including accessory fissure and normal liver parenchyma between the protruded masses, are described.

Transduction of human catalase mediated by an HIV-1 TAT protein basic domain and arginine-rich peptides into mammalian cells.

Antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) have been considered to have a beneficial effect against various diseases mediated by reactive oxygen species (ROS). Although a variety of modified recombinant antioxidant enzymes have been generated to protect against the oxidative stresses, the lack of their transduction ability into cells resulted in limited ability to detoxify intracellular ROS. To render the catalase enzyme capable of detoxifying intracellular ROS when added extracellularly, cell-permeable recombinant catalase proteins were generated. A human liver catalase gene was cloned and fused with a gene fragment encoding the HIV-1 Tat protein transduction domain (RKKRRQRRR) and arginine-rich peptides (RRRRRRRRR) in a bacterial expression vector to produce genetic in-frame Tat-CAT and 9Arg-CAT fusion proteins, respectively. The expressed and purified fusion proteins can be transduced into mammalian cells (HeLa and PC12 cells) in a time- and dose-dependent manner when added exogenously in culture medium, and transduced fusion proteins were enzymatically active and stable for 60 h. When exposed to H(2)O(2), the viability of HeLa cells transduced with Tat-CAT or 9Arg-CAT fusion proteins was significantly increased. In combination with transduced SOD, transduced catalase also resulted in a cooperative increase in cell viability when the cells were treated with paraquat, an intracellular antioxide anion generator. We then evaluated the ability of the catalase fusion proteins to transduce into animal skin. This analysis showed that Tat-CAT and 9Arg-CAT fusion proteins efficiently penetrated the epidermis as well as the dermis of the subcutaneous layer when sprayed on animal skin, as judged by immunohistochemistry and specific enzyme activities. These results suggest that Tat-CAT and 9Arg-CAT fusion proteins can be used in protein therapy for various disorders related to this antioxidant enzyme.