Semisolid Enteral Nutrients Alter the Pharmacokinetics of Orally Administered Levetiracetam in Rats

Enteral nutrients (ENs) affect the plasma drug concentration of orally co-administered drugs, particularly those of antiepileptic drugs, such as phenytoin and carbamazepine. However, few studies have reported the interactions of levetiracetam (LEV), an upcoming antiepileptic drug, with ENs. In this study we aimed to investigate the pharmacokinetics of LEV in 55 rats after oral co-administration of LEV with liquid or semisolid ENs. Compared with the control group, co-administration with Terumeal ® Soft significantly decreased the plasma LEV concentration at 0.5, 1, and 2 h and area under the plasma concentration-time curve from 0 to 3 h (AUC0→3h) (P < 0.01). However, the AUC0→3h of LEV remained unchanged following the administration of Terumeal ® Soft 2 h after the initial LEV administration. Moreover, co-administration with semisolid Racol® NF delayed the absorption of LEV without decreasing the AUC0→3h, whereas liquid Racol ® NF did not alter LEV pharmacokinetics. Thus, co-administration of LEV with Terumeal® Soft reduced the absorption of LEV from the gastrointestinal tract, which was prevented by administering Terumeal ® Soft 2 h after LEV administration. Semisolid Racol ® NF altered LEV pharmacokinetics without decreasing its gastrointestinal absorption. Our findings suggested that careful monitoring of the plasma LEV levels is necessary when co-administering LEV with Terumeal ® Soft, semisolid Racol ® NF, or any other semisolid ENs, to prevent the inadvertent effects of the interaction between LEV and ENs.

Interaction between phenytoin and enteral nutrients and its influence on gastrointestinal absorption

The gastrointestinal absorption of phenytoin (PHT), an antiepileptic drug, is often affected by its interaction with co-administered enteral nutrients through a nasogastric (NG) tube, resulting in decreased plasma PHT concentration. In this study, we measured the recovery rate (%) of PHT (Aleviatin^® powder) passed through an NG tube when co-administered with distilled water or enteral nutrients (F2α^®, Racol^® NF, Ensure Liquid^® and Renalen^® LP). We also measured plasma PHT levels in rats, after oral co-administration of PHT with enteral nutrients. We demonstrate that PHT recovery rate was close to 100 % in all cases after passage through the NG tube. In the rat study, the AUC_0→∞ of PHT concentration after oral administration significantly decreased when it was co-administered with F2α^® and Racol^® NF compared to distilled water. However, the AUC_0→∞ of PHT was unchanged when co-administered with F2α^® 2 h after initial PHT administration. We therefore conclude that the co-administration of PHT with F2α^® and Racol^® NF caused a reduction in the absorption of PHT from the gastrointestinal tract to the blood, without adsorption to the NG tube. The administration of enteral nutrients 2 h after PHT is one clear way to prevent a decrease in plasma PHT concentration.

Isolation and Characterization of Canine Factor IX

Canine plasma factor IX was purified to homogeneity by a combination of barium citrate precipitation and three-step column chromatographies of DEAE sepharose, heparin agarose and a monoclonal antifactor IX antibody-linked agarose. Canine factor IX has an apparent molecular size of 61 kDa, which is slightly smaller than that of human factor IX, as determined by denatured polyacrylamide gel electrophoresis. Its amino acid composition, amino-terminal and carboxyterminal amino acid sequences agreed well with those predicted from the reported cDNA. Unlike purified human factor IX, canine factor IX preparation often showed a discrete smaller molecular species (∼50 kDa) which was generated by a specific proteolytic cleavage between Arg310 and Val311. When purified canine factor IX was utilized as a standard for enzyme linked immunosorbent assay, the concentration of canine factor IX in the pooled normal dog plasma was determined to be 5.3 Μg/ml with 11.2% carbohydrate content (or 4.7 Μg/ml for its polypeptide chain moiety). Concentration of plasma factor IX antigen was measured in six severely affected, unrelated hemophilia B dogs. Four had factor IX antigen of less than 1% of the normal, and two had undetectable levels. The latter two had gross molecular abnormalities in their factor IX genes. Three obligate carrier females had variable but proportionately reduced factor IX antigen and factor IX coagulant activity levels. These results provide a quantitative method for measuring canine factor IX antigen which is a prerequisite for studying hemostasis and development of gene transfer approaches in the canine model of hemophilia B.

Age and Sex Dependent Regulation of the Factor IX Gene in Mice

Plasma factor IX and liver factor IX mRNA levels in two normal mouse strains (B6D2F1 and BALB/CJNIA) were determined in relation to aging and sex of the animals. With male B6D2F1 mice, mean plasma factor IX activity levels for the 14 and 21-22 month-old animals were found to be 124% and 226%, respectively, of the 5 month-old group. Similarly, liver factor IX mRNA levels for the same age animal groups were 145% and 227%, respectively, of the reference group. Mean plasma factor IX levels for the same age female animals were 132% and 175%, respectively, and were accompanied by similarly elevated liver factor IX mRNA levels, 119 and 175%, respectively, of the 5 month-old female group. Factor IX activity and mRNA levels for the 5,14 and 21-22 month-old female animal groups were lower than those of the corresponding male age groups by 25, 20 and 37%, and 20,36 and 38%, respectively. With BALB/CJNIA mice, similar correlation was observed between the advancing age and substantial elevations in the factor IX mRNA level as well as on the unequal factor IX mRNA levels in females and males.

These results indicate that the plasma factor IX level in both male and female mice is greatly elevated with aging, in general agreement with a similar phenomenon observed for human populations, and that this increase is due to a similar elevation in the factor IX mRNA level in the liver. In mice, both factor IX activity and mRNA levels are significantly higher in males than in females, which has not been described for humans.

Characterization of a Mouse Factor IX cDNA and Developmental Regulation of the Factor IX Gene Expression in Liver

A mouse factor IX cDNA was isolated and characterrzed. The cDNA was 1,837 bp in length and contained the coding region as well as short 5’ and 3’ untranslated sequences. Northern blot analysis of liver RNA showed two mRNA species of 3.2 kb (major) and 2.2 kb (minor) for the mouse factor IX. An antisgnse RNA probe prepared from the mouse cDNA was employed to determine the steady state level of factor IX mRNA in mouse liver at various developmental stages. The factor IX mRNA level was very low (2–5% of the adult level) during the gestational period until day –3 (gestational day 17) followed by a rapid increase at day –2 through birth. This phase of rapid increase was followed by a gradual increase before it reached the adult level at around 20 to 24 days. At birth, the factor IX mRNA level was found to be at about 43% of that of the adult. The rnRNA levels in mouse liver agreed well with the plasma factor IX activity levels. These results indicate that reduced factor IX activity in newborns is due to the low levels of factor IX mRNA available for translation.

Production of Recombinant Human Protein C In Vitro and In Vivo by Muscle Cells

Protein C plays a key role in a natural anticoagulation mechanism, and is also implicated in fibrinolytic and anti-inflammatory functions. Here we describe the production of biologically active human protein C by muscle-targeted gene transfer. Human protein C expression vectors were designed and constructed to produce human protein C in skeletal muscle cells. These vectors were tested in transient and stable transfections of SCID mice myoblasts. Stably transfected cells produced as high as 2.27 μg/106 cells/day. Human protein C produced had a relative activity of 92 ± 8% compared to the plasma derived human protein C, and was composed of α and β forms, 69% and 31%, respectively. After implantation of stably transfected myoblasts into the hind limb muscles of SCID mice, systemic stable production of human protein C in a range of 31-116 ng/ml serum was obtained up to at least 2.5 months.

Current address: J. Wang, Department of Hematology, Changai Hospital, 174 Changai Road, Yangpu District, Shangai 200433, China

FOLFIRI plus bevacizumab as second-line therapy in patients with metastatic colorectal cancer after first-line bevacizumab plus oxaliplatin-based therapy: the randomized phase III EAGLE study

EAGLE was a randomized, multicenter phase III study which evaluated the superiority of bevacizumab 10 mg/kg plus FOLFIRI compared with bevacizumab 5 mg/kg plus FOLFIRI in patients with mCRC previously treated with first-line bevacizumab plus an oxaliplatin-based regimen. The results suggest that the higher 10 mg/kg dose offers no clear clinical benefit compared with bevacizumab 5 mg/kg in this setting.

Background

A targeted agent combined with chemotherapy is the standard treatment in patients with metastatic colorectal cancer (mCRC). The present phase III study was conducted to compare two doses of bevacizumab combined with irinotecan, 5-fluorouracil/leucovorin (FOLFIRI) in the second-line setting after first-line therapy with bevacizumab plus oxaliplatin-based therapy.

Patients and methods

Patients were randomly assigned to receive FOLFIRI plus bevacizumab 5 or 10 mg/kg in 2-week cycles until disease progression. The primary end point was progression-free survival (PFS), and secondary end points included overall survival (OS), time to treatment failure (TTF), and safety.

Results

Three hundred and eighty-seven patients were randomized between September 2009 and January 2012 from 100 institutions in Japan. Baseline patient characteristics were well balanced between the two groups. Efficacy was evaluated in 369 patients (5 mg/kg, n = 181 and 10 mg/kg, n = 188). Safety was evaluated in 365 patients (5 mg/kg, n = 180 and 10 mg/kg, n = 185). The median PFS was 6.1 versus 6.4 months (hazard ratio, 0.95; 95% confidence interval [CI] 0.75–1.21; P = 0.676), and median TTF was 5.2 versus 5.2 months (hazard ratio, 1.01; 95% CI 0.81–1.25; P = 0.967), respectively, for the bevacizumab 5 and 10 mg/kg groups. Follow-up of OS is currently ongoing. Adverse events, including hypertension and hemorrhage, occurred at similar rates in both groups.

Conclusion

Bevacizumab 10 mg/kg plus FOLFIRI as the second-line treatment did not prolong PFS compared with bevacizumab 5 mg/kg plus FOLFIRI in patients with mCRC. If bevacizumab is continued after first-line therapy in mCRC, a dose of 5 mg/kg is appropriate for use as second-line treatment.

Clinical trial identifier

UMIN000002557.

β-cell induction in vivo in severely diabetic male mice by changing the circulating levels and pattern of the ratios of estradiol to androgens

Previously we have generated transgenic (Tg) mice developing severe diabetes early in life with a profound depletion of β-cells with β-cell-directed expression of inducible cAMP early repressor-Iγ. Only male mice continue to demonstrate hyperglycemia throughout life. To investigate this sexual dimorphism, we treated severely diabetic male Tg mice with orchiectomy (ORX) or 17β-estradiol (E2) pellet implantation alone or in combination with ORX and E2-implantation to change the circulating levels and patterns of the ratio of estradiol to androgens. In the Tg-ORX group, the blood-glucose levels decreased to a certain level within several weeks but never reached the female Tg-control level. In contrast, the Tg-ORX+E2 or Tg-E2 group showed a more rapid drop in blood glucose to the basal level with a substantial increase in β-cells, thus preventing the occurrence of severe diabetes in the male mice. The β-cells, not only within islet but also in and adjacent to ducts and scattered β-cell clusters, were strongly induced by 1 week after treatment, and the islet morphology dramatically changed. Enhanced β-cell induction in the ducts occurred concomitantly with markedly increased levels of pancreatic duodenal homeobox-1 and related transcription factors. The glucose-lowering and β-cell-increasing effects were independent of the age at which the treatment is started. These data provide evidence that the circulating level of E2 and the ratio of E2 to T greatly affect the blood glucose levels, the β-cell induction, and the islet morphology in diabetic male Tg mice. This novel mechanism offers great potential for developing strategies to increase the number of β-cells in vivo.

Heterogeneous nuclear ribonucleoprotein A3 is the liver nuclear protein binding to age related increase element RNA of the factor IX gene

Background

In the ASE/AIE-mediated genetic mechanism for age-related gene regulation, a recently identified age-related homeostasis mechanism, two genetic elements, ASE (age-related stability element) and AIE (age-related increase element as a stem-loop forming RNA), play critical roles in producing specific age-related expression patterns of genes.

Principal Finding

We successfully identified heterogeneous nuclear ribonucleoprotein A3 (hnRNP A3) as a major mouse liver nuclear protein binding to the AIE-derived RNAs of human factor IX (hFIX) as well as mouse factor IX (mFIX) genes. HnRNP A3 bound to the AIE RNA was not phosphorylated at its Ser³⁵⁹, while hnRNP A3 in the mouse liver nuclear extracts was a mixture of phosphorylated and unphosphorylated Ser³⁵⁹. HepG2 cells engineered to express recombinant hFIX transduced with adenoviral vectors harboring an effective siRNA against hnRNP A3 resulted in a substantial reduction in hFIX expression only in the cells carrying a hFIX expression vector with AIE, but not in the cells carrying a hFIX expression vector without AIE. The nuclear hnRNP A3 protein level in the mouse liver gradually increased with age, while its mRNA level stayed age-stable.

Conclusions

We identified hnRNP A3 as a major liver nuclear protein binding to FIX-AIE RNA. This protein plays a critical role in age-related gene expression, likely through an as yet unidentified epigenetic mechanism. The present study assigned a novel functional role to hnRNP A3 in age-related regulation of gene expression, opening up a new avenue for studying age-related homeostasis and underlying molecular mechanisms.

Age-related effects of regular physical activity on hemostatic factors in men

BACKGROUND

Age-related changes in blood coagulation and fibrinolytic factors are associated with an increase in risk of thrombotic events. The purpose of this study was to assess the effects of age, regular aerobic exercise and detraining on blood coagulation and fibrinolytic factors in men.

METHODS

Initially, 41 sedentary and 42 physically active men (20-64 years) were analyzed for plasma levels of coagulation and fibrinolytic factors. Twelve sedentary men were then subjected to 16-week aerobic exercise training and subsequent 2-week detraining. Their blood samples taken at rest were assayed for activity levels of prothrombin, coagulation factor (F) V, VII, VIII, IX, X, XI and XIII, antithrombin III, protein C and plasminogen, and for antigen levels of fibrinogen, prothrombin fragment 1 + 2 (F1 + 2), FIX, protein C, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1) and tPA/PAI-1 complex.

RESULTS

Plasma levels of most coagulation factors, particularly for fibrinogen and FIX antigens as well as FXIII activity significantly increased with aging in sedentary men, while that tendency disappeared in physically active men. By the exercise training, plasma antigen and/or activity levels of most blood coagulation factors except for prothrombin and FIX decreased. These training-effects, however, disappeared after detraining, and in some cases even rebounded to higher levels than those of pre-training. Plasma antigen levels of tPA, PAI-1 and tPA/PAI-1 complex decreased with the training and remained low even after detraining.

CONCLUSION

Regular aerobic exercises give complex effects on expression of hemostatic factors, overall favoring the hemostatic balance to less thrombotic, partly cancelling out the age effects.

Hybrid retroviral vector with MCK enhancers inserted in LTR for stable and specific expression of human factor IX in skeletal muscle

BACKGROUND

Retroviral vectors have been widely used to introduce foreign into various target cells in vitro, thus showing relatively high systemic delivery efficiency of various transgene products. The authors investigated the stability and efficiency of skeletal muscle-specific hybrid retroviral vectors in expression of human factor IX (FIX) in vitro and iv vivo.

METHODS

FIX cDNA in LIXSN vector was replaced with a FIX minigene containing splicing donor and splicing acceptor sequence of first intron of human FIX gene. Two copies of muscle creatine kinase enhancer (MCK, Me2) were inserted in forward or reverse orientation at NheI site of 3' long terminal repeat (LTR), resulting in two hybrid vectors, which were designated as LMe2IXm2SN(F) and LMe2IXm2SN(R), respectively. The vectors were tested in vitro and in vivo for stability and muscle-specificity of factor IX expression with SCID mice.

RESULTS

Muscle cells carrying vector with Me2 expressed significantly higher levels of FIX (up to 1800 ng/106.24 h) than those without Me2, thus suggesting that Me2 could specifically increase expression level of FIX in muscle cells. Myoblasts transduced with LMe2IXm2SN(R) produced much less FIX in vivo in SCID mice than LMe2IXm2SN(F). One or two copies of Me2 sequence were deleted in myoblasts transduced with LMe2IXm2SN(R) without changing the orientation of Me2.

CONCLUSIONS

LTR inserted with MCK enhancers can specifically increase human FIX expression in skeletal muscle cells in vitro and in vivo, and MCK enhancer should be positioned in the same orientation as that of LTR promoter.

Growth factor stimulation of matrix metalloproteinase expression and myoblast migration and invasion in vitro

We investigated the role of growth factors and fibronectin on matrix metalloproteinase (MMP) expression and on migration and invasion of mouse skeletal myoblasts in vitro. None of the growth factors tested significantly affected MMP-1 or MMP-2 activity as revealed by gelatin zymography, but both basic FGF (bFGF) and tumor necrosis factor (TNF)-alpha significantly increased MMP-9 activity (10- and 30-fold, respectively). The increase in secreted MMP-9 activity with TNF-alpha stimulation was due at least in part to an increase in MMP-9 gene transcription, because an MMP-9 promoter construct was approximately fivefold more active in TNF-alpha-treated myoblasts than in control myoblasts, as well as an increase in MMP-9 proteolytic activation. However, whereas fibronectin, bFGF, hepatocyte growth factor, and TGF-beta1 significantly augmented migration of mouse myoblasts, TNF-alpha did not, nor did PDGF-BB or IGF-I. Fibronectin and bFGF also significantly augmented invasion of myoblasts across a Matrigel barrier, and plasmin cotreatment potentiated whereas N-acetyl cysteine suppressed the effects of bFGF and fibronectin on myoblast migration and invasion. Finally, transient transfection with an MMP-9 overexpression construct had only minimal effects on myoblast migration/invasion, whereas overexpression of either MMP-2 or MMP-1 significantly augmented myoblast migration and invasion. These observations support the hypothesis that MMP activity is a necessary component of growth factor-mediated myoblast migration but suggest that other consequences of growth factor signaling are also necessary for migration to occur.

Myocardial fibrosis in mice with overexpression of human blood coagulation factor IX

Elevated circulatory levels of many blood coagulation factors are known to be a risk factor for deep vein thrombosis in humans. Here we report the first direct demonstration of a close association between elevated circulatory factor IX levels in mice with thrombosis as well as myocardial fibrosis. Transgenic mice overexpressing human factor IX at persistently high levels died at much younger ages than their cohorts expressing lower levels, or nontransgenic control animals. The median survival age of animals was inversely related to the circulatory levels of human factor IX. Prematurely dying animals had focal fibrotic lesions predominantly present in the left ventricular myocardium, and vasculatures in these lesions showed fibrin deposition. Thromboemboli were also present in other organs, including lung and brain. These observations support the hypothesis that persistently high circulatory levels of factor IX are a risk factor not only for thrombosis and/or thromboembolism, but also for myocardial fibrosis mimicking human myocardial infarction.

Limitation in use of heterologous reporter genes for gene promoter analysis. Silencer activity associated with the cloramphenicol acetyltransferase reporter gene

Various heterologous reporter genes have been widely used for the functional characterization of gene promoters. Many such studies often found weak to very strong silencer activities to be associated with specific parts of the basal promoter or further upstream regions. In this study, we carried out a systematic study on human blood coagulation factor IX (hFIX) and anti-coagulant protein C (hPC) genes, previously shown to have silencer activities associated with their 5'-flanking regions containing promoter sequences. With newly constructed chloramphenicol acetyltransferase (CAT) reporter vectors carrying hFIX or hPC gene promoter sequences, we confirmed the strong silencer activities associated with the regions nt -1895 through nt -416 of the hFIX gene or with the region nt -802 through nt -82 of the hPC gene. However, no such silencer activities associated with the specific regions were found when autologous hFIX cDNA, hFIX minigenes, or hPC minigenes were used as reporters in the expression vector system. Relative levels of CAT, hFIX, and hPC proteins produced in the transient assays correlated well with their mRNA levels. Human FIX minigene constructs containing a simian virus 40 (SV40) 3'-untranslated region (UTR) taken from the CAT reporter gene showed no silencer activity, indicating that SV40 3'-UTR sequence of the CAT reporter gene does not contribute to the silencer activity. Expression vectors constructed with the beta-galactosidase gene under the control of hFIX gene promoter sequences also showed no silencer activity associated with the region nt -1895 through nt -416. These findings indicate that silencer activities associated with specific regions of promoter sequences as analyzed with CAT reporter genes may represent artifacts specific to the CAT reporter genes. Our findings strongly suggest a need for re-examination of promoter characterizations of many eukaryotic genes, which have been studied to date with CAT reporter genes.

Bone marrow stromal cells as a genetic platform for systemic delivery of therapeutic proteins in vivo: human factor IX model

BACKGROUND

Hemophilia B is an X-linked bleeding disorder that results from a deficiency in functional coagulation factor IX (hFIX). In patients lacking FIX, the intrinsic coagulation pathway is disrupted leading to a lifelong, debilitating and sometimes fatal disease.

METHODS

We have developed an ex vivo gene therapy system using genetically modified bone marrow stromal cells (BMSCs) as a platform for sustained delivery of therapeutic proteins into the general circulation. This model exploits the ability of BMSCs to form localized ectopic ossicles when transplanted in vivo. BMSCs were transduced with MFG-hFIX, a retroviral construct directing the expression of hFIX. The biological activity of hFIX expressed by these cells was assessed in vitro and in vivo.

RESULTS

Transduced cells produced biologically active hFIX in vitro with a specific activity of 90% and expressed hFIX at levels of approximately 497 ng/10(6) cells/24 h and 322 ng/10(6) cells/24 h for human and porcine cells, respectively. The secretion of hFIX was confirmed by Western blot analysis of the conditioned medium using a hFIX-specific antibody. Transduced BMSCs (8 x 10(6) cells per animal) were transplanted within scaffolds into subcutaneous sites in immunocompromised mice. At 1 week post-implantation, serum samples contained hFIX at levels greater than 25 ng/ml. Circulating levels of hFIX gradually decreased to 11.5 ng/ml at 1 month post-implantation and declined to a stable level at 6.1 ng/ml at 4 months.

CONCLUSIONS

These findings demonstrate that genetically modified BMSCs can continuously secrete biologically active hFIX from self-contained ectopic ossicles in vivo, and thus represent a novel delivery system for releasing therapeutic proteins into the circulation.

Genetic mechanisms of age regulation of protein C and blood coagulation

Blood coagulation activity in humans increases with age. We previously identified two genetic elements, age-related stability element (ASE; GAGGAAG) and age-related increase element (AIE; unique stretch of dinucleotide repeats), which were responsible for age-related stable and increasing expression patterns, respectively, and together recapitulated normal age regulation of the human factor IX (hFIX) gene. Here we report the age-regulatory mechanisms of human anticoagulant protein C (hPC), which shows an age-stable pattern of circulatory levels. The murine protein C gene showed an age-related stable expression pattern in general agreement with that of the hPC. Through longitudinal analyses of transgenic mice carrying hPC minigenes, the hPC gene was found to have a functional age-related stability element (hPC ASE; CAGGAAG) in the 5'-upstream proximal region but was found to lack any age-related increase element. Three other ASE-like sequences present in the hPC gene, GAGGAAA and (G/C)AGGATG, also bound nuclear proteins but were not active in the age regulation of the hPC gene. Functional hPC ASE and hFIX ASE were apparently generated through convergent evolution, and hFIX ASE can fully substitute for the hPC ASE in conferring age-related stable expression pattern of the hPC gene. In the presence of the hPC ASE, hFIX AIE can convert the age-stable expression pattern of the hPC gene to a hFIX-like age-related increase pattern. These results support the universality of ASE and AIE functions across different genes. Clearance of hPC protein from the circulation was not significantly affected by age. We now have established the basic mechanisms responsible for the age-related increase of blood coagulation activity.

Treatment of hemophilia B in mice with nonautologous somatic gene therapeutics

The implantation of nonautologous cells encapsulated in immunoprotective microcapsules provides an alternative nonviral method for gene therapy. This strategy was successful in reversing the disease phenotypes of dwarfism and a lysosomal storage disease, mucopolysaccharidosis VII, in murine models. In this article we implanted transgenic hemophilic B mice with microcapsules enclosing factor IX-secreting C2C12 myoblasts to study the clinical potential of this approach in the treatment of hemophilia. Treated mice showed increased plasma factor IX levels as high as 28 ng of human factor IX per milliliter of plasma and decreased activated thromboplastin times (reduced by 20% to 29%). However, the level of factor IX decreased to baseline levels by day 7, coinciding with emergence of anti-human factor IX antibody, the titer of which increased greater than 10-fold by day 28. Monoclonal anti-CD4 antibodies were used to deplete CD4+ T cells to suppress the immune response against the recombinant factor IX. In the treated hemophilic mice, the anti-factor IX antibody response was totally suppressed to beyond day 28 accompanied by a significant decrease in activated thromboplastin time compared with that seen in untreated hemophilic mice. When the microcapsules were recovered from the intraperitoneal cavity after 38 days of implantation, the encapsulated cells continued to secrete factor IX at preimplantation levels, but both cell viability and microcapsule mechanical stability were reduced. Hence although the polymer chemistry of the microcapsules and cell viability may need to be improved for long-term delivery, nonautologous gene therapy with microencapsulated cells has been shown to be effective, at least for the short-term, in alleviating the hemophilic hemostatic anomaly. Coadministration of an immunosuppressant is effective in inhibiting antibody development against the delivered factor IX and should be considered for recipients at risk of inhibitor development.

Intrahepatic cholangiojejunostomy for unresectable malignant biliary tumors with obstructive jaundice

We reviewed our experience with intrahepatic cholangiojejunostomy as a palliative therapy for patients with unresectable malignant diseases involving the ductal confluence or the common hepatic duct. Fifteen patients with malignant biliary obstruction were treated by cholangiojejunostomy at our hospital. Two patients had intrahepatic cholangiocarcinoma, 7 had gallbladder carcinoma, 5 had bile duct carcionoma, and 1 had pancreatic carcinoma. Segment III cholangiojejunostomies were performed in 14 patients and segment V cholangiojejunostomy in 1. Contraindications for surgical resection were locoregional invasion of tumors involving the proper and/or common hepatic artery and portal vein in 15 patients and the presence of hepatic metastases in 6 patients. Liver metastases were detected in 5 of the 7 patients with gallbladder carcinoma. Postoperative complications occurred in 2 patients (13%), but there was no leakage of the cholangioenteric anastomosis in our series. There was no operative mortality after cholangiojejunostomy. Of the 9 patients who survived for more than 6 months after surgery, 7 showed a significant improvement in performance status (PS) (82 +/- 10%) 3 months after the surgery compared with the preoperative PS (70 +/- 7%). Four of the 9 patients had recurrent cholangitis as a late complication, but 4 were completely free from jaundice. Median survival after cholangioenteric bypass was 9 months (range, 2-25 months). With respect to tumor location, the median survival time was 4 months (range, 2-25 months) in patients with gallbladder carcinoma and 15.5 months (range, 12-22 months) in those with bile duct carcinoma. While the median survival period after surgery was only 3 months (range, 2 to 8 months) in the 5 patients with hepatic metastases from gallbladder carcinoma, 2 patients without liver metastasis survived for 9 and 25 months after segment III cholangioenteric bypass. In conclusion, cholangiojejunostomy can provide useful palliation for malignant biliary obstruction when combined with careful patient selection.

Delineation of prognostic biomarkers in prostate cancer

Prostate cancer is the most frequently diagnosed cancer in American men. Screening for prostate-specific antigen (PSA) has led to earlier detection of prostate cancer, but elevated serum PSA levels may be present in non-malignant conditions such as benign prostatic hyperlasia (BPH). Characterization of gene-expression profiles that molecularly distinguish prostatic neoplasms may identify genes involved in prostate carcinogenesis, elucidate clinical biomarkers, and lead to an improved classification of prostate cancer. Using microarrays of complementary DNA, we examined gene-expression profiles of more than 50 normal and neoplastic prostate specimens and three common prostate-cancer cell lines. Signature expression profiles of normal adjacent prostate (NAP), BPH, localized prostate cancer, and metastatic, hormone-refractory prostate cancer were determined. Here we establish many associations between genes and prostate cancer. We assessed two of these genes-hepsin, a transmembrane serine protease, and pim-1, a serine/threonine kinase-at the protein level using tissue microarrays consisting of over 700 clinically stratified prostate-cancer specimens. Expression of hepsin and pim-1 proteins was significantly correlated with measures of clinical outcome. Thus, the integration of cDNA microarray, high-density tissue microarray, and linked clinical and pathology data is a powerful approach to molecular profiling of human cancer.

Effects of a second intron on recombinant MFG retroviral vector

The retroviral vectors based on an MFG-type backbone have superior expression characteristics, in part, due to the presence of the retroviral chimeric intron (MFG intron). We tested the hypothesis that inclusion of a second intron in MFG vectors may influence packaging and/or LTR-driven transgene expression. We constructed two MFG retroviral vectors, MFG/hFIXc and MFG/hFIXm2, containing human factor IX (hFIX) cDNA without and with a 0.3-kb hFIX intron, respectively. When tested with primary mouse myoblasts or HepG2 cells in culture for transient expression activity, pMFG/hFIXm2 plasmid produced two-to-three fold higher hFIX than pMFG/hFIXc. These vectors produced equivalent retroviral titers from packaging cells. In transduced cells, the splicing of the MFG intron in the retroviral transcripts occurred at a similar efficiency; however, MFG/hFIXc virus gave two-fold higher hFIX expression than that of the MFG/hFIXm2 viral infection. Analyses of MFG/hFIXm2 virion RNA and transduced cell genomic DNA suggested that, although the hFIX intron containing viral RNA are packaged, these viruses fail to integrate their transgenes into the genome of transduced cells, suggesting a block at the reverse transcription and/or integration steps. Similar results were also obtained with the prototype vectors, LIXcSN and LIXm2SN, lacking the MFG intron. Together, these results suggest that a hFIX cDNA sequence in the retroviral vectors performs better over hFIX intron-containing minigene.

Impact of repeat hepatectomy on recurrent colorectal liver metastases

BACKGROUND

Hepatic recurrence is seen in approximately 40% of patients undergoing hepatectomy for colorectal metastases. This study was designed to assess the risks and clinical benefits of repeat hepatectomy for those patients.

METHODS

Twenty-six patients underwent repeat hepatectomy for hepatic recurrence, and their clinical data were retrospectively reviewed for operative morbidity and mortality, performance level, and survival.

RESULTS

There was no operative mortality after repeat hepatectomy. Operative bleeding was significantly increased in the second hepatectomy; but operating time, duration of hospital stay, and performance status after the second hepatectomy were comparable with those of the initial hepatectomy. The median survival time from the second hepatectomy was 31 months, and the 3- and 5-year survival rates were 62% and 32%, respectively. A short disease-free interval (6 months or less) between the initial hepatectomy and diagnosis of hepatic recurrence in the remnant liver was significantly associated with poor survival after the second hepatectomy.

CONCLUSIONS

Repeat resection contributed to clinical benefits for selected patients with hepatic recurrence after the initial hepatectomy for colorectal liver metastases. However, appearance of hepatic recurrence within 6 months or less after the initial hepatectomy is a poor prognostic factor for repeat hepatectomy.

Impact of repeat hepatectomy on recurrent colorectal liver metastases

BACKGROUND

Hepatic recurrence is seen in approximately 40% of patients undergoing hepatectomy for colorectal metastases. This study was designed to assess the risks and clinical benefits of repeat hepatectomy for those patients.

METHODS

Twenty-six patients underwent repeat hepatectomy for hepatic recurrence, and their clinical data were retrospectively reviewed for operative morbidity and mortality, performance level, and survival.

RESULTS

There was no operative mortality after repeat hepatectomy. Operative bleeding was significantly increased in the second hepatectomy; but operating time, duration of hospital stay, and performance status after the second hepatectomy were comparable with those of the initial hepatectomy. The median survival time from the second hepatectomy was 31 months, and the 3- and 5-year survival rates were 62% and 32%, respectively. A short disease-free interval (6 months or less) between the initial hepatectomy and diagnosis of hepatic recurrence in the remnant liver was significantly associated with poor survival after the second hepatectomy.

CONCLUSIONS

Repeat resection contributed to clinical benefits for selected patients with hepatic recurrence after the initial hepatectomy for colorectal liver metastases. However, appearance of hepatic recurrence within 6 months or less after the initial hepatectomy is a poor prognostic factor for repeat hepatectomy.

Lymphoepithelial cyst of the pancreas: report of a case

An extremely rare case of a lymphoepithelial cyst (LEC) of the pancreas is described herein. A pancreatic cystic tumor was initially detected in a 50-year-old man at a medical checkup. On admission, his serum carbohydrate antigen (CA) 19-9 level was 8100 U/ml and a computed tomography scan revealed a well-circumscribed multilocular cystic tumor in the pancreatic head and body. Magnetic resonance cholangiopancreatography showed no communication between the pancreatic ducts and the tumor. A distal pancreatectomy with lymph node dissection was performed because the lesion was suspected to be a mucinous cystadenoma or cystadenocarcinoma of the pancreas. However, histological examination revealed that the cyst was lined by stratified squamous epithelium and surrounded by lymphoid tissue. thereby confirming the diagnosis of LEC of the pancreas. The superficial layer of squamous epithelium and the cystic contents were found to be immunohistologically positive for CA19-9. Establishing a preoperative diagnosis of LEC is quite difficult because it resembles other cystic neoplasms of the pancreas in radiographic features and is frequently associated with an elevation of serum tumor markers such as CA19-9.

Portal vein thrombosis caused by microwave coagulation therapy for hepatocellular carcinoma: report of a case

Microwave coagulation therapy (MCT) is one of the treatment modalities for patients with hepatocellular carcinoma (HCC). A 67-year-old man with liver cirrhosis underwent MCT during a laparotomy for a deeply located HCC (2.5 cm in diameter) at the border of the anterior and posterior segments of the right hepatic lobe. Two weeks after MCT, he complained of abdominal fullness. Portal vein thrombosis (PVT) was diagnosed because he had massive ascites and an echogenic mass in the portal vein on abdominal ultrasonography. PVT was successfully treated by fibrinolytic therapy with a selective infusion of urokinase via the superior mesenteric artery (SMA). There have been few reports on PVT as a complication of MCT. Attention should be paid to the possible occurrence of PVT as a critical complication after MCT for liver tumors adjacent to the portal vein. Fibrinolytic therapy via the SMA is thus considered to be an effective approach for PVT after MCT.

Carrier analysis of a moderately affected haemophilia B family

Here we report the successful genetic diagnosis of a pregnant caucasian female patient whose family has a history of moderate haemophilia B. While restriction fragment length polymorphism (RFLP) analysis was not informative, nucleotide sequencing of the factor IX genes of the patient's family members determined that her mother and one of her two sisters were carriers of the mutation C31008T, which causes a Thr296Met transition. In contrast, the pregnant female herself and her other sister were found to carry only normal alleles. Plasma factor IX activity and antigen levels supported these findings.

The roles of platelet-activating factor and endothelin-1 in renal damage after total hepatic ischemia and reperfusion

BACKGROUND

This study was designed to verify the involvement of platelet-activating factor (PAF) in renal damage associated with hepatic ischemia and reperfusion (HIR) injury through the release of endothelin (ET)-1 and to determine the modulating effect of a specific PAF receptor antagonist on these insults in rats.

METHODS

Male rats pretreated with either normal saline as a vehicle (NS group) or intravenous TCV-309, a PAF receptor antagonist (TCV group), were subjected to 120 min of total hepatic ischemia under an extracorporeal portosystemic shunt. Plasma aspartate transaminase, creatinine, blood urea nitrogen, and ET-1 levels and the relative renal wet weight were determined under nonischemic conditions and at 1, 3, and 6 hr of reperfusion after hepatic ischemia. Changes in mean arterial blood pressure and renal tissue blood flow measurements in the kidney were determined throughout the experiment.

RESULTS

Increased plasma aspartate transaminase, creatinine, blood urea nitrogen, and ET-1 levels and the relative renal wet weight after HIR in the NS group were significantly suppressed by TCV-309 pretreatment. Mean arterial blood pressure and renal tissue blood flow after HIR in the TCV group were significantly improved when compared with those in the NS group. These effects resulted in attenuation of structural hepatic and renal damage with the improvement of 7-day survival (62%).

CONCLUSIONS

The present study demonstrates that renal damage as well as critical liver injury is produced after reperfusion following 120 min of total hepatic ischemia. A PAF receptor antagonist may be therapeutically useful to protect against these types of damage via indirect modulation of plasma ET-1 levels.

The PHSRN sequence induces extracellular matrix invasion and accelerates wound healing in obese diabetic mice

The PHSRN sequence of the plasma fibronectin (pFn) cell-binding domain induces human keratinocytes and fibroblasts to invade the naturally serum-free extracellular matrices of sea urchin embryos. The potency of acetylated, amidated PHSRN (Ac-PHSRN-NH(2)) is significantly increased, making it more active on a molar basis than the 120-kDa cell-binding domain of pFn. Arginine is important to this activity because PHSAN and PHSEN are inactive, as is a randomized sequence peptide, Ac-HSPNR-NH(2). One treatment with Ac-PHSRN-NH(2) stimulates reepithelialization and contraction of dermal wounds in healing-impaired, obese diabetic C57BL6/KsJ db/db mice. Wound closure is equally rapid in treated db/db and db/+ mice and may be more rapid than in untreated nondiabetic db/+ littermates. In contrast, treatment with either Ac-HSPNR-NH(2) or normal saline (NS) has no effect. Analysis of sectioned db/db wounds shows that, in contrast to treatment with Ac-HSPNR-NH(2) or NS, a single Ac-PHSRN-NH(2) treatment stimulates keratinocyte and fibroblast migration into wounds, enhances fibroplasia and vascularization in the provisional matrix, and stimulates the formation of prominent fibers that may be associated with wound contraction.

Kinetics of recombinant adeno-associated virus-mediated gene transfer

Recombinant adeno-associated virus (rAAV) vectors have been shown to be useful for efficient gene delivery to a variety of dividing and nondividing cells. Mechanisms responsible for the long-term, persistent expression of the rAAV transgene are not well understood. In this study we investigated the kinetics of rAAV-mediated human factor IX (hFIX) gene transfer into human primary myoblasts and myotubes. Transduction of both myoblasts and myotubes occured with a similar and high efficiency. After 3 to 4 weeks of transduction, rAAV with a cytomegalovirus (CMV) promoter showed 10- to 15-fold higher expression than that with a muscle-specific creatine kinase enhancer linked to beta-actin promoter. Factor IX expression from transduced myoblasts as well as myotubes reached levels as high as approximately 2 microgram of hFIX/10(6) cells/day. Southern blot analyses of high-molecular-weight (HMW) cellular genomic and Hirt DNAs isolated from rAAV/CMVhFIXm1-transduced cells showed that the conversion of single-stranded vector genomes to double-stranded DNA forms, but not the level of the integrated forms in HMW DNA, correlated with increasing expression of the transgene. Together, these results indicate that rAAV can transduce both proliferating and terminally differentiated muscle cells at about the same efficiency, that expression of transgenes increases linearly over their lifetime with no initial lag phase, and that increasing expression correlates with the appearance of double-stranded episomal rAAV genomes. Evidence showing that the rAAV virions can copackage hFIX, presumably nonspecifically, was also obtained.

Genetic mechanisms of age regulation of blood coagulation: factor IX model

Blood coagulation capacity increases with age in healthy individuals, apparently because of increases in the plasma concentration of most procoagulant factors. This phenomenon may play an important role in the advancing age-associated increase of cardiovascular diseases and thrombosis. Through longitudinal analyses of transgenic mice, we recently identified 2 critical age-regulatory elements, AE5' and AE3', which are together essential for age regulation of the normal human factor IX (hFIX) gene. AE5', present in the long interspersed repetitive element-derived sequence of the 5' upstream region, containing polyomavirus enhancer activator-3 or a closely related element, is responsible for age-stable expression of the gene and functions in a position-independent manner. AE3', present in the middle of the 3' untranslated region, is responsible for age-associated elevation of hFIX mRNA levels in the liver. Presence of both AE5' and AE3' is needed to recapitulate normal age regulation of the hFIX gene. Because factor IX clearance from the circulation is not significantly affected by age, age regulation of hFIX levels is achieved primarily by a combination of stabilization of gene transcription and age-dependent increases in the mRNA levels, which are presumably due to increasing mRNA stabilization. The stage is now set for further systematic studies of the genetic and molecular mechanisms of age regulation of other key coagulation and anticoagulation factors in hopes of understanding the overall age regulation of blood coagulation.

Genetic and molecular mechanisms of age regulation (homeostasis) of blood coagulation

Blood coagulation plays a critical role not only in hemostasis but also in many physiological and pathological conditions. Epidemiological studies have shown that blood coagulation capacity in humans increases with age. Towards understanding the underlying mechanisms, the age regulation of factor IX, a key blood coagulation factor, was extensively studied. A series of human factor IX minigenes, consisting of various components of the human factor IX gene, were constructed and subjected to systematic analyses with HepG2 cells in culture and over the entire life span of transgenic mice. These studies identified critical gene structures that are essential for the unique age-dependent expression patterns of the human factor IX gene--one acting by stabilizing gene transcription and another increasing the amount of mRNA present, presumably by augmenting mRNA stability. These studies have set the stage for analyzing the overall age-based regulatory mechanisms of blood coagulation.

Anti-invasive, antitumorigenic, and antimetastatic activities of the PHSCN sequence in prostate carcinoma

Using naturally serum-free SU-ECM basement membranes as invasion substrates showed that plasma fibronectin was necessary to stimulate invasion by DU 145 human and metastatic MATLyLu (MLL) rat prostate carcinoma cells. This activity mapped to the PHSRN sequence, which induced invasion through alpha5beta1 integrin. PHSCN, a competitive inhibitor, blocked both PHSRN- and serum-induced invasion. Acetylated, amidated PHSCN (Ac-PHSCN-NH2) was 30-fold more potent; however, Ac-HSPNC-NH2 was inactive. Rats receiving injections s.c. with 100,000 MLL cells were treated systemically by i.v. injection three times weekly with 1 mg of either Ac-PHSCN-NH2 or Ac-HSPNC-NH2 beginning 24 h later, three times weekly with 1 mg of Ac-PHSCN-NH2 beginning only after surgery to remove large (2 cm) MLL tumors, or were left untreated. MLL tumors grew rapidly in Ac-HSPNC-NH2-treated and in untreated rats. MLL tumor growth in rats treated with Ac-PHSCN-NH2 beginning 1 day after MLL cell injection was reduced by 99.9% during the first 16 days of treatment, although subsequent tumor growth occurred. MLL tumor cryosections immunostained with anti-PECAM-1 showed that Ac-PHSCN-NH2 inhibited neovascularization by 12-fold during this time. Whether initiated after MLL cell injection or only after MLL tumor removal, Ac-PHSCN-NH2 treatment reduced the numbers of MLL lung colonies and micrometastases by 40- to >100-fold, whereas Ac-HSPNC-NH2 was inactive. Thus, Ac-PHSCN-NH2 may be a potent antitumorigenic and antimetastatic agent for postsurgical use prior to extensive metastasis.

Intrauterine gene transfer: gestational stage-specific gene delivery in mice

Intrauterine gene transfer in mice by intraplacental microinjection of recombinant adenoviral or retroviral vectors carrying beta-galactosidase (beta-gal) reporter gene was analyzed in relation to gestational stage, viral titer and promoters. After injections of viral vectors on days 9.5, 11.5 or 14.5 post coitum (p.c.), embryos, fetuses and adult animals were analyzed for beta-gal expression on days 13.5 p.c., 18.5 p.c. and at 2 months of age, respectively. Injection of adenoviral vectors on day 9.5 or day 11.5 p.c. resulted in high beta-gal expression in the heart or liver, respectively. Injection on either day also gave expression in other tissues including vasculature and hindbrain. This temporal pattern of adenoviral transduction correlated with the expression level of integrin beta3 subunit, which is known to be a component involved in adenoviral transduction. Adenovirus-mediated intrauterine gene transfer resulted in persistent beta-gal expression in multiple cell foci in the liver and hearts of 2-month-old adult animals treated in utero, indicating stable integration of the transgene into the host cell genome at a low frequency. Although at low efficiency, injection of retroviral vector on day 9.5 and 11.5 p.c. resulted in beta-gal expression in embryonic liver, while day 9.5 p.c. injection resulted in persistent beta-gal expression in 2-month-old adult heart. This is the first study to show gestational stage-specific gene transfer via intraplacental microinjection of adenoviral vectors.

Genetic mechanisms of age regulation of human blood coagulation factor IX

Blood coagulation capacity increases with age in healthy individuals. Through extensive longitudinal analyses of human factor IX gene expression in transgenic mice, two essential age-regulatory elements, AE5' and AE3', have been identified. These elements are required and together are sufficient for normal age regulation of factor IX expression. AE5', a PEA-3 related element present in the 5' upstream region of the gene encoding factor IX, is responsible for age-stable expression of the gene. AE3', in the middle of the 3' untranslated region, is responsible for age-associated elevation in messenger RNA levels. In a concerted manner, AE5' and AE3' recapitulate natural patterns of the advancing age-associated increase in factor IX gene expression.

Complete nucleotide sequence, origin of isoform and functional characterization of the mouse hepsin gene

Hepsin, a type-II membrane-associated serine protease, has been implicated in cell growth and development as well as possible initiation of blood coagulation. Here, we report on the complete nucleotide sequence, functional characterization of key structural features and the promoter of the mouse hepsin gene. The gene has a size of approximately 17 kb, and is composed of 12, 13, or 14 exons depending on alternative intron splicings - one in the 5'-UTR and the other two in the second intron. The latter two, which occur in approximately half of the hepsin transcripts, generate a hepsin mRNA species with an extra exon, which is responsible for producing a hepsin isoform with a unique 20-residue sequence inserted in the cytoplasmic portion of hepsin. Most hepsin transcripts have the 5'-UTR intron spliced, and its splicing can occur independently of the other alternative splicings. The transcriptional initiation site was determined to be 636 bp upstream of the first ATG site in a cytidine-rich region. The 5'-flanking region of hepsin up to nucleotide 274 showed a substantial promoter activity in HepG2 cells, with its expression activity sevenfold higher in the presence of the 5'-UTR intron sequence in comparison to that without the intron sequence. The basal promoter region contains potential binding sites for several transcription factors including SP1, AP2, C/EBP, LF-A1, and E box, which may be responsible for ubiquitous, but liver- and kidney-preferred tissue expression of the hepsin gene.