Protective effects of acetylbergenin against carbon tetrachloride-induced hepatotoxicity in rats

The present study was undertaken to investigate whether or not the hepatoprotective activity of acetylbergenin was superior to bergenin in carbon tetrachloride (CCl4)-intoxicated rat. Acetylbergenin was synthesized by acetylating bergenin, which was isolated from Mallotus japonicus. The hepatoprotective effects of acetylbergenin were examined against CCl4-induced liver damage in rats by means of serum and liver biochemical indices. Acetylbergenin was administered orally once daily for 7 successive days, then a 0.5 ml/kg mixture of CCl4 in olive oil (1:1) was intraperitoneally injected at 12 h and 36 h after the final administration of acetylbergenin. Pretreatment with acetylbergenin reduced the elevated serum enzymatic activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and gamma-glutamyltransferase in a dose dependent fashion. Acetylbergenin also prevented the elevation of hepatic malondialdehyde formation and depletion of glutathione content dose dependently in CCl4-intoxicated rats. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored to almost normal levels. The results of this study strongly suggest that acetylbergenin has potent hepatoprotective activity against CCl4-induced hepatic damage in rats by glutathione-mediated detoxification as well as having free radical scavenging activity. In addition, acetylbergenin doses of 50 mg/kg showed almost the same levels of hepatoprotective activity as 100 mg/kg of bergenin, indicating that lipophilic acetylbergenin is more active against the antihepatotoxic effects of CCl4 than those of the much less lipophilic bergenin.

Effects of cysteine on the pharmacokinetics and pharmacodynamics of intravenous and oral azosemide in rats with protein-calorie malnutrition

The effects of cysteine on the pharmacokinetics and pharmacodynamics of azosemide were investigated after intravenous (10 mg/kg) and oral (20 mg/kg) administration to male Sprague-Dawley rats fed on 23% protein diet (control rats), and 5% protein diet with (rats with PCMC) or without (rats with PCM) oral cysteine (250 mg/kg, twice daily for the fourth week) for 4 weeks. After intravenous administration to rats with PCMC, some pharmacokinetic parameters restored fully or more than the level of control rats; the time-averaged nonrenal clearance (2.70 versus 2.32 ml/min/kg) and apparent volume of distribution at steady state (160 versus 189 ml/kg) were comparable to those in control rats, however, the terminal half-life (34.7 versus 57.2 min) and mean residence time (73.3 versus 99.3 min) were significantly shorter, area under the plasma concentration-time curve from time zero to time infinity (AUC, 1930 versus 2680 microg min/ml) was significantly smaller, and time-averaged renal (2.24 versus 1.21 ml/min/kg) and total body (CL, 4.98 versus 3.65 ml/min/kg) clearances were significantly faster than those in control rats. This could be mainly due to significantly faster renal clearance and at least partly due to increased cytochrome P450 1A2 activity by cysteine supplementation. After intravenous administration to rats with PCMC, the total amount of 8-hr urinary excretion of unchanged azosemide was significantly greater (457 versus 305 microg/g body weight), however, the 8-hr urine output (15.3 versus 31.1 ml/g kidney) was not significantly different between control rats and rats with PCMC. This could be due to the fact that urine output seemed to reach an upper plateau from 10 mg/kg dose of azosemide in rats.

Effect of graded running on esophageal motility and gastroesophageal reflux in fed volunteers

The effects of different grades of running on esophageal motility and gastroesophageal reflux in the fed state were evaluated. We studied healthy volunteers (male: 12, age: 27 +/- 5 yr) using ambulatory esophageal manometry, pH catheter and portable digital data recorder. Each exercise was performed 30 min after meal, with 20 min of rest between exercises. Subjects exercised on a treadmill at 40% and 70% maximal heart rate. The number of gastroesophageal reflux episodes, the duration of esophageal acid exposure and percent time pH below 4 were significantly (p < 0.01) increased during exercise at 70% maximal heart rate. The frequency of contraction (contraction/min) (p < 0.05), frequency of repetition (p < 0.01), percent of simultaneous contraction (p < 0.01), percent of above 100 mmHg amplitude (p < 0.05), and frequency of 2-peak contraction (p < 0.01) were significantly increased during exercise at 70% maximal heart rate. However, median amplitude and median duration showed no significant changes between each exercise session. Postprandial running exercises induce gastroesophageal reflux, which correlates with exercise intensity. These effects are mediated by disorganized esophageal motility.

Quantitative mRNA expression analysis from formalin-fixed, paraffin-embedded tissues using 5' nuclease quantitative reverse transcription-polymerase chain reaction

Analysis of gene expression and correlation with clinical parameters has the potential to become an important factor in therapeutic decision making. The ability to analyze gene expression in archived tissues, for which clinical followup is already available, will greatly facilitate research in this area. A major obstacle to this approach, however, has been the uncertainty about whether gene expression analyses from routinely archived tissues accurately reflect expression before fixation. In the present study we have optimized the RNA isolation and reverse transcription steps for quantitative reverse transcription-polymerase chain reaction (RT-PCR) on archival material. Using tissue taken directly from the operating room, mRNAs with half-lives from 10 minutes to >8 hours were isolated and reverse transcribed. Subsequent real-time quantitative PCR methodology (TaqMan) on these cDNAs gives a measurement of gene expression in the fixed tissues comparable to that in the fresh tissue. In addition, we simulated routine pathology handling and demonstrate that this method of mRNA quantitation is insensitive to pre-fixation times (time from excision to fixation) of up to 12 hours. Therefore, it should be feasible to analyze gene expression in archived tissues where tissue collection procedures are largely unknown.

Differential display reveals downregulation of the phospholipid transfer protein (PLTP) at the mRNA level in brains of patients with Down syndrome

The phospholipid transfer protein (PLTP) shows a wide variety of functions including transfer of phospholipids and other lipid-like substances. Performing gene hunting in brain of patients with Down syndrome (DS) we detected the absence of a fragment identified as PLTP. Cerebellum of 4 controls, 7 patients with DS, 5 patients with Alzheimer's disease (AD) were used for differential display and for quantification of mRNA steady state levels of the isomer PLTP-1 by blotting methods. Differential display showed the absence of a cDNA fragment and cloning, sequencing and gene bank work revealed 100% homology with human PAC 337018 on chromosome 20q containing the PLTP gene. The PLTP gene in turn consists of at least three different PLTP-isomers. Based on these results, a 450 bp cDNA fragment of the PLTP-isomer I (PLTP I) was isolated and amplified by PCR, serving as probe for the PLTP-1 isomer and its expression level was found to be significantly reduced in cerebellum of patients with DS. Biologically, the downregulation of PLTP maybe involved in the pathology of DS as phospholipids not only are of importance for membrane biogenesis and structure but also in the regulation of cellular metabolism, signaling and growth. In the brain, phospholipids in addition are integral constituents of myelins and synaptosomes (Johnson etc) and deficient PLTP levels may account for the deteriorated functions described to occur in DS brain.

The asymmetric catalytic aldol reaction of allenolates with aldehydes using n-fluoroacyl oxazaborolidine as the catalyst

The asymmetric catalytic aldol reaction of silyl allenolates with aldehydes has been achieved by using N-C(3)F(7)CO oxazaborolidine as the catalyst. The fluoroacyl group of the catalyst was found to be crucial for control of enantioselectivity. The reaction provides the first enantioselective approach to beta-halo Baylis-Hillman-type adducts.

Mitochondrial dysfunction by gamma-irradiation accompanies the induction of cytochrome P450 2E1 (CYP2E1) in rat liver

Multiple biological effects are induced by ionizing radiation through dysfunction of cellular organelles, direct interaction with nucleic acids and production of free radical species. The expression of cytochrome P450s was assessed in the livers of 60Co gamma-irradiated rats. Three gray (G) of gamma-irradiation caused CYP2E1 induction with a 3.6-fold increase in the mRNA at 24 h, whereas the expression of CYP1A2 and CYP3A was not changed. Pharmacokinetics of chlorzoxazone, a specific substrate of CYP2E1, was studied in 3 G-irradiated rats. The area under the plasma concentration-time curve from time zero to infinity of 6-hydroxychlorzoxazone and the amount of 6-hydroxychlorzoxazone excreted in 8 h urine were both significantly greater than those in control rats. Hepatic CYP2E1 was not induced in rats exposed to 0.5-1 G of gamma-rays. Rats irradiated at 6-9 G accumulated doses of gamma-rays exhibited smaller increases in the mRNA due to liver injury than those irradiated at a single dose of 3 G gamma-rays. The plasma glucose and insulin levels were not altered in rats with 3 G of gamma-irradiation. As the exposure level of gamma-irradiation increased, the activity of hepatic aconitase, a key enzyme in energy metabolism in mitochondria, was 30-90% decreased. The amount of mitochondrial DNA per gram of wet liver was 50% decreased in rats exposed to 3 G of gamma-rays. These results demonstrated that gamma-ray irradiation at the exposure level inducing organelle dysfunction induced CYP2E1 in the liver, which might be associated with mitochondrial damage, but not with alterations in glucose or insulin levels.

Size analysis of automobile soot particles using field-flow fractionation

Soot particles emitted from various automobile engines are analyzed for size distributions using field-flow fractionation (FFF). Soot samples are prepared for FFF analysis using a three-step procedure, where a layer of soot particles is focused between the layers of n-hexane and water, followed by dispersing of particles in water containing 0.05% Triton X-100. The mean diameters determined by FFF show similar trends with those obtained from dynamic light scattering (DLS) and scanning electron microscopy (SEM). Data from FFF are also compared with those from an on-line scanning mobility particle sizer (SMPS). SMPS size distributions extend further to larger size than those of FFF distributions, which indicates the three-step sample preparation procedure effectively disaggregates the agglomerated particles. Although the amount of particulate matter (PM) emitted from a heavy-duty diesel engine is much higher than that from a light-duty diesel engine, the size distributions of soot particles show no significant difference between heavy- and light-duty diesel engines. The engine-operating mode (engine speed and load rate) does not seem to affect significantly the size distribution of soot particles. It was found that the PM from a turbocharged diesel engine contains a higher percentage of particles smaller than 100 nm than an engine with a naturally aspirated (NA) air-inhalation system. As for gasoline engines, the PM collected after the catalytic converter has a narrower size distribution than those collected before and has a higher percentage of particles smaller than 100 nm.

Long-term delivery of all-trans-retinoic acid using biodegradable PLLA/PEG-PLLA blended microspheres

All-trans-retinoic acid (atRA) has been proved to be effective against several malignancies in human clinical trials. However, in many patients who were treated with atRA, the cancer relapsed after a brief remission. One reason for such relapse is that atRA is metabolized by specific P450s that are induced in the liver during prolonged atRA treatments. In order to overcome such a drawback of atRA, we prepared biodegradable microspheres to provide continuous release of atRA for a long period of time. These biodegradable microspheres were prepared by poly(L-lactide) (PLLA) and polyethylene glycol (PEG)-PLLA diblock copolymers (PLE) in various blending ratios to control the release rate of atRA. As the PLE content in microsphere was increased, the density of the hydrophilic PEG block of PLE on microsphere surfaces increased and the microspheres were dispersed well in PBS without any surfactants. Various release patterns of atRA were obtained according to PLE and atRA contents in the microspheres. Especially, the pseudo-zero-order release profiles were observed for 5 weeks when the contents of PLE and atRA in the microspheres were above 4 wt.%.

Site-specific mutations in the mature form of human IL-18 with enhanced biological activity and decreased neutralization by IL-18 binding protein

IL-18 can be considered a proinflammatory cytokine mediating disease as well as an immunostimulatory cytokine that is important for host defense against infection and cancer. The high-affinity, constitutively expressed, and circulating IL-18 binding protein (IL-18BP), which competes with cell surface receptors for IL-18 and neutralizes IL-18 activity, may act as a natural antiinflammatory as well as immunosuppressive molecule. In the present studies, the IL-18 precursor caspase-1 cleavage site was changed to a factor Xa site, and, after expression in Escherichia coli, mature IL-18 was generated by factor Xa cleavage. Mature IL-18 generated by factor Xa cleavage was fully active. Single point mutations in the mature IL-18 peptide were made, and the biological activities of the wild-type (WT) IL-18 were compared with those of the mutants. Mutants E42A and K89A exhibited 2-fold increased activity compared with WT IL-18. A double mutant, E42A plus K89A, exhibited 4-fold greater activity. Unexpectedly, IL-18BP failed to neutralize the double mutant E42A plus K89A compared with WT IL-18. The K89A mutant was intermediate in being neutralized by IL-18BP, whereas neutralization of the E42A mutant was comparable to that in the WT IL-18. The identification of E42 and K89 in the mature IL-18 peptide is consistent with previous modeling studies of IL-18 binding to IL-18BP and explains the unusually high affinity of IL-18BP for IL-18.

Syntheses and evaluation of pyrido[2,3-dlpyrimidine-2,4-diones as PDE 4 inhibitors

The syntheses and in vitro evaluation of a new series of pyrido[2,3-d]pyrimidine-2,4-diones bearing substituents at C-3 and/or C-4 positions on the pyridine ring are described. Some of these compounds, especially 51 and 6f, were found to be potent phosphodiesterase 4 (PDE 4) inhibitors exhibiting improved ratio of PDE 4 inhibitory activity:rolipram binding assay (RBA).

Vascular endothelial growth factor expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin through nuclear factor-kappa B activation in endothelial cells

Vascular endothelial growth factor (VEGF) induces adhesion molecules on endothelial cells during inflammation. Here we examined the mechanisms underlying VEGF-stimulated expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin in human umbilical vein endothelial cells. VEGF (20 ng/ml) increased expression of ICAM-1, VCAM-1, and E-selectin mRNAs in a time-dependent manner. These effects were significantly suppressed by Flk-1/kinase-insert domain containing receptor (KDR) antagonist and by inhibitors of phospholipase C, nuclear factor (NF)-kappaB, sphingosine kinase, and protein kinase C, but they were not affected by inhibitors of mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) 1/2 or nitric-oxide synthase. Unexpectedly, the phosphatidylinositol (PI) 3'-kinase inhibitor wortmannin enhanced both basal and VEGF-stimulated adhesion molecule expression, whereas insulin, a PI 3'-kinase activator, suppressed both basal and VEGF-stimulated expression. Gel shift analysis revealed that VEGF stimulated NF-kappaB activity. This effect was inhibited by phospholipase C, NF-kappaB, or protein kinase C inhibitor. VEGF increased VCAM-1 and ICAM-1 protein levels and increased leukocyte adhesiveness in a NF-kappaB-dependent manner. These results suggest that VEGF-stimulated expression of ICAM-1, VCAM-1, and E-selectin mRNAs was mainly through NF-kappaB activation with PI 3'-kinase-mediated suppression, but was independent of nitric oxide and MEK. Thus, VEGF simultaneously activates two signal transduction pathways that have opposite functions in the induction of adhesion molecule expression. The existence of parallel inverse signaling implies that the induction of adhesion molecule expression by VEGF is very finely regulated.

First and second generation total synthesis of the teicoplanin aglycon

Full details of studies leading to the total synthesis of the teicoplanin aglycon are provided. Key elements of the first generation approach (26 steps from constituent amino acids, 1% overall) include the coupling of an EFG tripeptide precursor to the common vancomycin/teicoplanin ABCD ring system and sequential DE macrocyclization of the 16-membered ring with formation of the diaryl ether via a phenoxide nucleophilic aromatic substitution of an o-fluoronitroaromatic (80%, 3:1 atropisomer diastereoselection) followed by 14-membered FG ring closure by macrolactamization (66%). Subsequent studies have provided a second generation total synthesis which is shorter, more convergent, and highly diastereoselective (22 steps, 2% overall). This was accomplished by altering the order of ring closures such that FG macrolactamization (95%) preceded coupling of the EFG tripeptide to the ABCD ring system and subsequent DE ring closure. Notably, DE macrocyclization via diaryl ether formation on substrate 57, the key intermediate in the latter approach incorporating the intact FG ring system, occurred with exceptional diastereoselection for formation of the natural atropisomer (>10:1, 76%) without problematic C(2)(3) epimerization provided the basicity of the reaction is minimized.

Familial British dementia: expression and metabolism of BRI

Vidal et al. (1999. Nature 399: 776-778) discovered that the underlying genetic lesion in familial British dementia (FBD) is a T-A transversion at the termination codon of a membrane protein, termed BRI. The mutation creates an arginine codon; translational read-through generates a novel protein, termed BRI-L, that is extended by 11 amino acids at the carboxyl-terminus. BRI-L is the precursor of the ABri peptide, a component of amyloid deposits in FBD brain. We demonstrate that both BRI and its mutant counterpart are constitutively processed by furin, resulting in the secretion of carboxyl-terminal peptide derivatives that correspond to all, or part of, ABri. Notably, elevated levels of peptides are generated from the mutant BRI precursor, suggesting that subtle conformational alterations at the carboxyl-terminus may influence furin-mediated processing. We have examined BRI/BRI-L processing by other members of the prohormone convertase (PC) family (PACE4, LPC, PC 5/6) and found that these enzymes also process BRI, albeit inefficiently. Moreover, BRI-L processing by the other PC members is severely compromised. Finally, our electron microscopic studies reveal that synthetic ABri peptides assemble into insoluble beta-pleated fibrils. Collectively, our results support the view that enhanced furin-mediated processing of mutant BRI generates amyloidogenic peptides that initiate the pathogenesis of FBD.

Decreased brain histamine-releasing factor protein in patients with Down syndrome and Alzheimer's disease

Histamine-releasing factor (HRF) stimulates secretion of histamine that is widely distributed in brain and released as neurotransmitter. Several studies suggested that histaminergic deficits could contribute to the cognitive decline in Alzheimer's disease (AD). Based upon deranged histamine metabolism in brain of patients with AD and Down Syndrome (DS), we aimed to study HRF in brain of AD and DS. We used two-dimensional gel electrophoresis, matrix-assisted laser desorption ionization mass spectroscopy and specific software to quantify HRF. HRF was significantly reduced in temporal cortex, thalamus and caudate nucleus of DS and in temporal cortex of AD as compared to controls. This is the first report to show decreased HRF brain levels in DS and AD suggesting the explanation for the decreased cognitive function in neurodegenerative/dementing disorders.

Huge calcified aneurysm of the sinus of Valsalva

Aneurysms of the sinus of Valsalva often remain undiagnosed until they rupture. A 61-year-old man had a huge, heavily calcified unruptured aneurysm, originating from the right sinus of Valsalva, detected incidentally on a chest radiograph taken for the diagnosis of cardiomegaly. Two-dimensional echocardiography revealed pericardial effusion with a huge calcified mass compressing the right ventricular outflow tract. The Doppler color-flow echocardiogram showed blood flow from the aortic root into the aneurysm. A chest computed tomographic scan revealed a large thrombosed aneurysm originating from the aortic root and measuring 10x10 cm. After pericardiocentesis, cardiac catheterization was performed, which showed that the right ventricular systolic pressure had elevated to 80 mmHg. Aortic root aortography demonstrated a huge unruptured calcified aneurysm in the sinus of Valsalva arising from the right coronary sinus. The patient underwent surgical correction to prevent aneurysmal rupture and to relieve the right ventricular outflow obstruction.

Detection of genetic changes in anal intraepithelial neoplasia (AIN) of HIV-positive and HIV-negative men

Compared with HIV-negative individuals, HIV-positive individuals have a higher prevalence of anogenital human papillomavirus (HPV) infection, as well as a higher incidence of HPV-associated anal cancer. Little is currently known of chromosomal changes occurring in anal intraepithelial neoplasia (AIN), the probable precursor to anal cancer. Genetic changes in AIN were characterized by comparative genomic hybridization (CGH) in a study of samples obtained from 19 HIV-positive and 11 HIV-negative men. The proportion with genetic changes significantly increased with the severity of the histopathologic grade with none diagnosed as (0%) AIN 1; 5 of 17 (29%) as AIN 2; and 5 of 9 (56%) AIN 3 showing genetic changes (p = .02). This correlation was also found in study subjects who had multiple biopsies with different grades of pathology concurrently or serially over time. The most common regional DNA copy number change was gain mapped to chromosome arm 3q (12% of AIN 2 and 33% of AIN 3). This alteration was previously reported to be commonest alteration in cervical cancer, which suggests a common molecular pathway for these two HPV-associated anogenital neoplasias.

Growth inhibition and chemosensitivity of poorly differentiated human thyroid cancer cell line (NPA) transfected with p53 gene

BACKGROUND

We investigated whether retroviral p53 transfection could enhance growth inhibition and chemosensitivity in a p53 mutant papillary thyroid cancer cell line (NPA).

METHODS

NPA cells were transfected with either LXSN/p53 or mock infection in the presence of Adriamycin. Gene expression was confirmed by western blotting. Nude mice were injected subcutaneously with NPA cells after transfection with either LXSN/p53 or mock infection on opposite sides, and the tumor growth was compared.

RESULTS

There was a dose-dependent inhibition of tumor growth with LXSN/p53 transfection. Tumor growth was inhibited more by p53 gene transfection relative to mock transfection in the presence of Adriamycin.

CONCLUSION

These treatment modalities could be beneficial in the treatment of p53 mutant positive thyroid cancers.

Microsatellite instability in synchronous gastric carcinomas

Synchronous gastric carcinomas are found in 4% to 10% of all gastric carcinomas, and the tumor multiplicity is believed to be related to genetic predisposition. To investigate the role of mismatch repair error in synchronous gastric carcinomas, we analyzed the microsatellite instability (MSI) status of 101 cancers from 48 gastrectomy specimens and compared them with 149 solitary gastric carcinomas. Multiple synchronous gastric carcinomas are characterized by slightly older age, predominance in males, early stage and lower lymph node metastasis. Among the 48 cases, 8 (18 lesions) were associated with a gastric adenoma (type I) and 40 (83 lesions) were not associated with a gastric adenoma (type II). The MSI+ rate was 50% in the type I and 8.4% in the type II synchronous gastric carcinomas (p < 0.001), while that of solitary gastric carcinomas was 9.4%. In addition, the frameshift mutation rates of the TGF-betaRII, BAX and hMSH3 genes in the type I synchronous carcinomas were higher than those in the type II synchronous carcinomas. These findings indicate that a defect in the mismatch repair system might play a role in the carcinogenesis of a minor subset of multiple gastric carcinomas associated with adenomas.

Combination chemotherapy utilizing continuous infusion of intermediate-dose cytarabine for refractory or recurrent acute myeloid leukemia

Between October 1991 and December 1998, 19 patients (12 males and 7 females) with refractory (six patients) or recurrent (13 patients) AML were treated with a combination chemotherapy of cytarabine given by continuous infusion over 24-h at a rate of 1 upward arrow g/m2 per day for 5 days along with idarubicin (12 upward arrow mg/m2 per day x 3) and etoposide (150 mg /m(2) per day x 3). Median age of the patients was 28 years (range, 15--61). Seven (37%) of 19 patients achieved complete remission (CR) with median CR duration of 6.7 months (range, 2.5--61.4+). Two patients are surviving for long term (50.1 and 62.6 months). Myelosuppression associated with chemotherapy was severe. Median recovery time to ANC over 500/microl was 28 days (range, 25--59). A significant proportion of patients experienced grade III-VI non-hematologic toxicities including nausea/vomiting (32%), liver function abnormality (32%), and diarrhea (16%). No central nervous system (CNS) toxicity was observed. Our study showed that the administration of cytarabine at a dose of 1 g/m(2) per day by continuous intravenous infusion for 5 days along with idarubicin and etoposide was feasible. Further studies are necessary to elucidate optimum dose and schedule of cytarabine in a setting of refractory or relapsed acute myeloid leukemia (AML).

Effective treatment of established murine collagen-induced arthritis by systemic administration of dendritic cells genetically modified to express IL-4

Dendritic cells (DC) are APCs that are able to stimulate or inhibit immune responses, depending on levels of expression of MHC class I and II costimulatory molecules and cytokines. Our previous studies have suggested that the observed contralateral effect, where injection of a vector carrying certain immunomodulatory genes into one joint resulted in inhibition of arthritis in untreated joints, is mediated by in vivo modification of DC. Therefore, we have examined the ability of genetically modified DC to suppress established murine collagen-induced arthritis (CIA) after i.v. delivery. IL-4 has been shown to partially reduce the severity of CIA after repeated injection of recombinant protein or by injection of an adenoviral vector expressing IL-4. Here we demonstrate that i.v. injection of immature DC, infected with an adenoviral vector expressing IL-4, into mice with established CIA resulted in almost complete suppression of disease, with no recurrence for up to 4 wk posttreatment. Injection i.v. of fluorescently labeled DC demonstrated that the cells rapidly migrated to the liver and spleen after 6 h and to the lymph nodes by 24 h. In culture, spleen cells from DC/IL-4-treated mice produced less IFN-gamma after stimulation by collagen than did control groups. In addition, DC/IL-4 administration decreased the level of specific Abs against type II collagen, in particular the IgG2 Th1 isotype 14 days posttreatment. These results demonstrate the ability to treat effectively established murine arthritis by systemic administration of DC expressing IL-4.

Epitheliomesenchymal transdifferentiation of cultured RPE cells

Retinal pigment epithelium (RPE) cells of the proliferative vitreoretinopathy (PVR) membrane take on the shape of fibroblasts and participate in fibrosis, thus deviating from the character of epithelial cells. This study was undertaken to evaluate RPE cell transdifferentiation in vitro. During the culture of porcine RPE cells, primary and 10th-passaged RPE cells were investigated for cell growth in response to transforming growth factor (TGF) beta(2), change of phenotype and amount in collagen synthesis as well as expression of alpha-smooth-muscle actin (alpha-SMA). TGF-beta(2) inhibited the proliferation of the primary cultures of RPE cells in a dose-dependent manner, while the spindle-shaped 10th-passaged RPE cells were not inhibited by TGF-beta(2). The 10th-subcultured cells did not show much difference in the quality of collagen synthesis, other than type VIII collagen which was not produced. Collagen synthesis was dose-dependently stimulated by TGF-beta(2). The stimulation by TGF-beta(2) in the 10th-passaged RPE cells was much greater than in primary RPE cells. The 10th-subcultured RPE cells produced substantial alpha-SMA compared to alpha-SMA production by primary RPE cells. These results were also observed by confocal laser microscopy. These findings indicated that RPE metaplasia resulting in a change of biological cell behavior might be a necessary predisposing step in the development of PVR.

Expression of Fas and Fas-related molecules in human hepatocellular carcinoma

Many tumor cells, including hepatocellular carcinoma (HCC), express both Fas and its ligand on their surfaces, and it has remained a mystery why such cells do not spontaneously become apoptotic. In the current study, we analyzed the alterations of Fas structure and the expression of Fas and Fas ligand (FasL) and of Fas pathway inhibitors, including soluble Fas (sFas), Fas-associated phosphatase-1 (FAP-1), and bcl-2, in 50 cases of human HCC. Monoallelic loss of the Fas gene, as determined by loss of heterozygosity with intragenic polymorphisms, was observed in 5 of the 34 informative cases (15%), but none of the 50 cases showed Fas gene mutation. Expression of Fas and FasL was detected in 44 (88%) and 50 (100%) cases, respectively. sFas messenger RNA, as analyzed by in situ reverse-transcription polymerase chain reaction was expressed in 42 of the 50 cases (84%), and FAP-1 expression was observed in 40 of the 50 cases (80%). In contrast, none of the 50 cases showed bcl-2 expression. Our results showed that the majority of the HCCs (88%) coexpressed a death receptor, Fas and its cognate ligand, FasL, but all HCCs showed one or more alterations of the Fas pathway molecules known to inhibit Fas-mediated apoptosis. These findings suggest that the expression of sFas and FAP-1 and, in part, loss of Fas expression, rather than Fas gene alteration or bcl-2 expression, may be involved in the Fas resistance of HCC in vivo and that these mechanisms may play important roles in the pathogenesis of human HCC. HUM PATHOL 32:250-256.

High-performance liquid chromatographic analysis of a new neuroprotective agent for ischemia-reperfusion damage, KR-31378

A high-performance liquid chromatographic method was developed for the determination of a neuroprotective agent for ischemia-reperfusion damage, KR-31378, in human plasma and urine and in rat tissue homogenates. The method involved deproteinization of the the biological samples with 0.5 volumes of saturated Ba(OH)2, 0.5 volumes of 0.04 M ZnSO4 and 1 volume of acetonitrile. A 80-microl aliqout of the supernatant was injected onto a reversed-phase C18 column. The mobile phase, 50 mM triethylamine acetate : acetonitrile : tetrahydrofuran (65:30:5, v/v/v), was run at a flow rate of 1.0 ml/min. The column effluent was mornitored by a ultraviolet detector set at 310 nm. The retention time of KR-31378 was approximately 6.5 min. The detection limits of KR-31378 in human plasma and urine and rat tissue homogenates were 0.2, 0.5 and 0.5 microg/ml, respectively. The coefficients of variation (within-day and between-day) were below 13.6% for human plasma and urine and rat homogenates. No interferences from endogenous substances were found.