Experimental Models of Acute Respiratory Distress Syndrome: Clinical Relevance and Response to Surfactant Therapy

Surfactant therapy for acute respiratory distress syndrome (ARDS) has shown encouraging results in animal studies, but not always in clinical trials. Efficacy of this therapy may be limited to ARDS caused by indirect injury, but mistiming of its application in clinical trials may be responsible for the discouraging results. In addition, the therapy may not last long enough to be effective. In rats with acidified milk aspiration, the effects of aerosolized surfactant therapy followed by inhalation of aerosolized dextran (molecular weight, 40,000) last significantly longer than those of aerosolized surfactant therapy alone. This mode of surfactant therapy could lead to better results since it can be started and repeated at any time.

Localized gene delivery using antibody tethered adenovirus from polyurethane heart valve cusps and intra-aortic implants

The present study investigated a novel approach for gene therapy of heart valve disease and vascular disorders. We formulated and characterized implantable polyurethane films that could also function as gene delivery systems through the surface attachment of replication defective adenoviruses using an anti-adenovirus antibody tethering mechanism. Our hypothesis was that we could achieve site-specific gene delivery to cells interacting with these polyurethane implants, and thereby demonstrate the potential for intravascular devices that could also function as gene delivery platforms for therapeutic vectors. Previous research by our group has demonstrated that polyurethane elastomers can be derivatized post-polymerization through a series of chemical reactions activating the hard segment amide groups with alkyl bromine residues, which can enable a wide variety of subsequent chemical modifications. Furthermore, prior research by our group investigating gene delivery intravascular stents has shown that collagen-coated balloon expandable stents can be configured with anti-adenovirus antibodies via thiol-based chemistry, and can then tether adenoviral vectors at doses that lead to high levels of localized arterial neointima expression, but with virtually no distal spread of vector. Thus, we sought to create two-device configurations for our investigations building on this previous research. (1) Polyurethane films coated with Type I collagen were thiol activated to permit covalent attachment of anti-adenovirus antibodies to enable gene delivery via vector tethering. (2) We also formulated polyurethane films with direct covalent attachment of anti-adenovirus antibodies to polyurethane hard segments derivatized with alkyl-thiol groups, thereby also enabling tethering of replication-defective adenoviruses. Both formulations demonstrated highly localized and efficient transduction in cell culture studies with rat arterial smooth muscle cells. In vivo experiments with collagen-coated polyurethane films investigated an abdominal aorta implant model in pigs using a button configuration that simulated the blood contacting environment of a vascular graft. One week explants of the collagen-coated polyurethane films demonstrated 14.3+/-2.5% of neointimal cells on the surface of the implant transduced with green fluorescent protein - adenovirus (AdGFP) vector loadings of 1 x 10(8) PFU. PCR studies demonstrated no detectable vector DNA in blood or distal organs. Similarly, polyurethane films with direct attachment of antivector antibodies to the surface were used in sheep pulmonary valve leaflet replacement studies, simulating the blood contacting environment of a prosthetic heart valve cusp. Polyurethane films with antibody tethered AdGFP vector (10(8) PFU) demonstrated 25.1+/-5.7% of attached cells transduced in these 1 week studies, with no detectable vector DNA in blood or distal organs. In vivo GFP expression was confirmed with immunohistochemistry. It is concluded that site-specific intravascular delivery of adenoviral vectors for gene therapy can be achieved with polyurethane implants utilizing the antivector antibody tethering mechanism.

208.Zona pellucida vaccines for fertility control of brushtail possums in New Zealand

Introduced marsupial brushtail possums (Trichosurus vulpecula) are a major pest in New Zealand because of their impacts on conservation values and agricultural production. Immunologically-based fertility control (immunocontraception) offers an effective and humane alternative approach to possum management. The zona pellucida (ZP) is an extracellular coat around all mammalian eggs and an attractive target for the development of immunocontraceptive vaccines. Antibodies against ZP are ovary-specific and act by preventing sperm from binding and penetrating the ova and/or by disrupting the development of follicles or early embryo. The aim of these studies was to test the efficacy of possum-derived ZP antigens for their ability to elicit sustained immune responses and cause infertility, and to assess a range of options for development of a bait-delivered contraceptive vaccine. Alloimmunisation with possum ZP2 and ZP3 proteins showed that self-ZP antigens elicited strong humoral immune responses and reduced the fertility of female possums by 72-80%. Several potentially possum-specific immunocontraceptive peptides have been identified by linear epitope mapping and amino acid alignment and are being tested for their ability to reduce fertility. Recent trials have demonstrated that possums mount immune responses against ZP antigens delivered in transgenic plants and bacterial ghosts. Research on antigen and specific peptide identification, non-target effects and delivery systems is ongoing. Research supported by NZ Foundation for�Research Science & Technology, Marsupial CRC and NZ Animal Health Board.

DNA delivery from an intravascular stent with a denatured collagen-polylactic-polyglycolic acid-controlled release coating: mechanisms of enhanced transfection

We previously demonstrated that DNA-polylactic-polyglycolic acid (PLGA)-coated stents can deliver genes to the arterial wall with reporter expression involving 1% of neointimal cells. The present study investigated a novel formulation utilizing denatured collagen in DNA-stent coatings; denatured collagen was hypothesized to enhance gene transfer due to adhesion molecule interactions and actin-related mechanisms. Arterial smooth muscle cells (SMCs) cultivated on denatured collagen had significantly greater plasmid DNA (beta-galactosidase) transfection than SMC grown on native collagen (18.3+/-1.2 vs 1.0+/-0.1%, P<0.001). The denatured-collagen effect was completely blocked with anti-alpha(v)beta(3) integrin antibody. SMCs cultivated on native collagen supplemented with tenascin-C (TN-C), a protein recognized by alpha(v)beta(3) integrins, showed a 33-fold increase in transfection compared to control (P<0.001); this effect was also blocked with anti-alpha(v)beta(3) antibody. We observed that cells grown on denatured collagen had marked F-actin-enriched stress fibers and intense perinuclear G actin, compared to those grown on native collagen, which demonstrated F-actin-enriched focal adhesions without perinuclear G-actin localization. Cytochalasin-D, an F actin depolymerizing agent, caused significantly increased SMC transfection in cells cultivated on native collagen compared to control cells (18.0+/-1.8 vs 3.02+/-0.9%, P<0.001) further supporting the view that actin-related cytoskeletal changes influence transfection. A denatured-collagen-PLGA composite vascular stent coating similarly resulted in increased plasmid DNA green fluorescent protein (GFP) expression compared to controls (P<0.001) in SMC cultures; the increased transfection was blocked by anti-alpha(v)beta(3) antibody. Pig coronary studies comparing denatured-collagen-PLGA-coated stents containing plasmid DNA (encoding GFP) to coated stents without DNA demonstrated 10.8% of neointimal cells transfected; this level of expression was almost an order of magnitude greater than previously reported with a DNA delivery stent. It is concluded that denatured collagen incorporated into plasmid DNA-stent coating formulations may increase the level of gene expression in vitro and in vivo because of integrin-related mechanisms and associated changes in the arterial smooth muscle cell actin cytoskeleton.

Expression of cytochromes P450 4F4 and 4F5 in infection and injury models of inflammation

Lipopolysaccharide (LPS) treatment of rats suppresses CYP 4F4 and 4F5 expression by 50 and 40%, respectively, in a direct fashion occurring in the liver. This contention is borne out by essentially parallel dose-dependent changes observed upon treatment of rat hepatocyte cultures with LPS. An alternate avenue of triggering the inflammatory cascade is traumatic brain injury by controlled cortical impact. Such injury brings about a dramatic change in the expression of CYP 4F4 and 4F5 mRNA which reaches its greatest effect 24 h after impact compared with sham-operated but uninjured controls. At time points after 24 h the expression of both isoforms increases dramatically reaching highest levels at 2 weeks post-injury. These changes in mRNA expression are mirrored by changes in protein expression. The results are consistent with the notion that immediately after injury concentrations of leukotriene and prostaglandin mediators are elevated by decreased CYP 4F concentrations. As time after injury increases those conditions reverse. Increased CYP 4F expression leads to diminished concentrations of leukotriene and prostaglandin mediators and then to recovery and repair.

In vivo studies of polypyrrole/peptide coated neural probes

Neural probes are micromachined multichannel electrode arrays that facilitate the functional stimulation and recording of neurons in the peripheral and central nervous system. For long-term implantations, surface modification is necessary for maintaining the stable connection between electrodes and neurons. The conductive polymer polypyrrole (PPy) and synthetic peptide DCDPGYIGSR were co-deposited on the electrode surface by electrochemical polymerization. The stability of PPy/DCDPGYIGSR coatings was tested in soaking experiments. It was found that the peptide was entrapped in the PPy film and did not diffuse away within 7 weeks of soaking in DI water. Coated probes were implanted in guinea pig brain for periods of 1, 2 and 3 weeks. Recording tests were performed and the impedance was monitored. The explanted probes and tissue were examined by immunocytochemical studies. Significantly more neurofilament positive staining was found on the coated electrode which indicated that the coatings had established strong connections with the neuronal structure in vivo. Good recordings were obtained from the coated sites that had neurons attached. First week tissue sections had no significant gliosis. In week 2, a layer of non-neuronal tissue consisting of mostly meningeal fibroblasts and ECM protein including at least fibronectin was formed around the probe tracks of both coated and uncoated probes. Astrocytes started to form a loosely organized layer by the end of the third week.

Assembly of alternating polycation and DNA multilayer films by electrostatic layer-by-layer adsorption

The assembly of alternating DNA and positively charged poly(dimethyldiallylammonium chloride) (PDDA) multilayer films by electrostatic layer-by-layer adsorption has been studied. The real-time surface plasmon resonance (BIAcore) technique was used to characterize and monitor the formation of multilayer films in solution in real time continuously. Electrochemical impedance spectroscopy (EIS) and UV-vis absorbance measurements were also used to study the film assembly, and linear film growth was observed. All the results indicate that the uniform multilayer can be obtained on the poly(ethylenimine)- (PEI-) coated substrate surface. The kinetics of the adsorption of DNA on PDDA surface was also studied by the real-time BIAcore technique; the observed rate constant was calculated using a Langmuir model (k(obs) = (1.28 +/- 0.08) x 10(-2) s(-1).

Comparison of the structures of natural and re-established populations of Ascaris in humans in a rural community of Jiangxi, China

To compare the structures of natural and re-established populations of Ascaris in humans, universal (mass) chemotherapy was carried out at the beginning and the end of the study year using pyrantel pamoate. Worms expelled within 48 h of treatment were collected, their sex determined, and measurements made of length, width and weight. Length was used as the criterion for estimating the developmental stage of the worms. In comparison with the natural population, the reestablished population displayed similar sex ratio as well as distribution patterns among individuals and age groups of the host. However, the mean worm burden of the re-established population was significantly decreased, with a reduction of burdens in children aged 5-9 years. Also, the re-established population showed significant changes in population structure and worm measurements in that it comprised more immature and less fertile males, less fertile and more senile females, smaller and lighter males, larger (but not heavier) females than the natural population. The results suggested that the reestablished Ascaris population did not restore to its original status in relation to mean density, composition and fecundity. Therefore, universal treatment once a year should decrease the transmission of Ascaris in humans. Combined with previous results for the same study sites, the present findings also indicated that caution is warranted to avoid misleading conclusions when using prevalence and faecal egg counts as parameters for evaluating the success of control programmes.

Infrared Spectra of Phthalocyanine and Naphthalocyanine in Sandwich-Type (Na)phthalocyaninato and Porphyrinato Rare-Earth Complexes. II. The Effects of Rare-Earth Ionic Size on the IR Characteristics of Naphthalocyaninein Bis(naphthalocyaninato) Rare-Earth Complexes

The infra-red (IR) spectroscopic data for a series of 28 homoleptic substituted bis(naphthalocyaninato) rare-earth complexes M(2,3-Nc*)2 [M = Y, La–Lu except Pm; H2Nc* = 3(4),12(13),21(22),30(31)-tetra(tert-butyl)-2,3- naphthalocyanine (H2TBNc) and 3,4,12,13,21,22,30,31-octa(dodecylthio)-2,3-naphthalocyanine (H2ODTNc)] have been collected with a resolution of 2 cm–1. These neutral sandwich complexes are radicals due to their composition (Nc*)2–MIII(Nc*)–, wherein the unpaired electron is delocalized over both macrocycles on the vibrational time scale. Compared to spectra obtained with low resolution, such as 4 cm–1, a larger number of vibrational modes could be distinguished. The IR spectra for M(ODTNc)2 are much simpler than those of M(TBNc)2, revealing the relatively higher symmetry of the former molecules. By analogy with bis(phthalocyaninato) rare-earth counterparts, the pyrrole stretching absorptions at 1314–1317 and 1323–1330�cm–1 for M(TBNc)2 and at 1316–1327 cm–1 for M(ODTNc)2 are assigned to the IR marker bands of the respective naphthalocyanine mono-anion radicals. These marker bands, together with those at 746–753 cm–1 assigned to C–H wagging, 1350–1355 cm–1 attributed to pyrrole stretchings, and 1389–1394 cm–1 due to naphthalene stretchings, have been found to shift slightly to higher energy along with the rare-earth contraction, clearly demonstrating the effect of rare-earth ionic radius.

TECA hybrid artificial liver support system in treatment of acute liver failure

AIM: To assess the efficacy and safety of TECA type hybr id artificial liver support system (TECA-HALSS) in providing liver function of detoxification, metabolism and physiology by treating the patients with acute liv er failure (ALF).

METHODS: The porcine liver cells (1-2) × 10¹⁰ were separated from the Chinese small swine and cultured in the bioreactor of TECA-BALSS at 37.0 °C and circulated through the outer space of the hollow fiber tubes in BALSS. The six liver failure patients with various degree of hepatic coma were treated by TECA-HALSS and with conventional medicines. The venous plasma of the patients was separated by a plasma separator and treated by charcoal adsorbent or plasma exchange. The plasma circulated through the inner space of the hollow fiber tubes of BALSS and mixed with the patients’ blood cells and flew back to their blood circulation. Some small molecular weight substances were exchanged between the plasma and porcine liver cells. Each treatment lasted 6.0-7.0 h. Physiological and biochemical parameters were measured before, during and after the treatment.

RESULTS: The average of porcine liver cells was (1.0-3.0) × 10¹⁰ obtained from each swine liver using our modified enzymatic digestion method. The survival rate of the cells was 85%-93% by trypan blue stain and AO/PI fluorescent stain. After cultured in TECA-BALSS bioreactor for 6 h, the survival rate of cells still remained 70%-85%. At the end of TECA-HALSS treatment, the levels of plasma NH₃, ALT, TB and DB were significantly decreased. The patients who were in the state of drowsiness or coma before the treatment improved their appetite significantly and regained consciousness, some patients resumed light physical work on a short period after the treatment. One to two days after the treatment, the ratio of PTA increased warkedly. During the treatment, the heart rates, blood pressure, respiration condition and serum electrolytes (K⁺, Na⁺ and Cl^-) were stable without thrombosis and bleeding in all the six patients.

CONCLUSION: TECA-HALSS treatment could be a rapid, safe and efficacious method to provide temporary liver support for patients with ALF.

Cross-talk among estrogen receptor, epidermal growth factor, and insulin-like growth factor signaling in breast cancer

Since the cloning of the estrogen receptor alpha (ERalpha) and subsequent identification of a second distinct form of ER, termed ERbeta, a large volume of research has begun to define the molecular mechanisms of ER action. However, although great progress has been made, ER action is still poorly understood. It is expected that a better understanding of ER action may lead to novel strategies and targets for breast cancer prevention and treatment. One of the early-realized functions of the ER was regulation of growth factor signaling, but the degree of interaction between these two mitogenic signaling pathways could not have been anticipated. Recent evidence suggests that the ER and the growth-factor-signaling pathways intersect and directly interact at every level of signal transduction. The resulting synergism between ER and growth factors has been documented both in normal breast development and, importantly, in breast cancer progression and antiestrogen resistance. In this review, we will highlight our current understanding of the molecular mechanisms of cross-talk between ER and growth-factor-signaling pathways.

Acute G-CSF therapy is not protective during lethal E. coli sepsis

We investigated whether decreases in circulating polymorphonuclear neutrophils (PMN) during lethal Escherichia coli (E. coli) sepsis in canines are related to insufficient host granulocyte colony-stimulating factor (G-CSF). Two-year-old purpose-bred beagles had intraperitoneal E. coli-infected or -noninfected fibrin clots surgically placed. By 10 to 12 h following clot, both infected survivors and nonsurvivors had marked increases (P = 0.001) in serum G-CSF levels (mean peak G-CSF ng/ml +/- SE, 1,931 +/- 364 and 2,779 +/- 681, respectively) compared with noninfected controls (134 +/- 79), which decreased at 24 to 48 h. Despite increases in G-CSF, infected clot placement caused delayed (P = 0.06) increases in PMN (mean +/- SE change from baseline in cells x 10(3)/mm(3) at 24 and 48 h) in survivors (+3.9 +/- 3.9 and +13.8 +/- 3.6) compared with noninfected controls (+13.1 +/- 2.8 and +9.1 +/- 2.5). Furthermore, infected nonsurvivors had decreases in PMN (-1.4 +/- 1.0 and -1.1 +/- 2.3, P = 0.006 compared with the other groups). We next investigated whether administration of G-CSF immediately after clot placement and continued for 96 h to produce more rapid and prolonged high levels of G-CSF after infection would alter PMN levels. Although G-CSF caused large increases in PMN compared with control protein from 2 to 48 h following clot in noninfected controls, it caused much smaller increases in infected survivors and decreases in infected nonsurvivors (P = 0.03 for the ordered effect of G-CSF comparing the three groups). Thus insufficient host G-CSF is unlikely the cause of decreased circulating PMN in this canine model of sepsis. Other factors associated with sepsis either alone or in combination with G-CSF itself may reduce increases or cause decreases in circulating PMN.

Effect and mechanism of electronic magnetic pulse on peripheral lymphocytes in dogs

OBJECTIVE

To study the effects of electronic magnetic pulse (EMP) on peripheral lymphocytes in dogs and to explore the mechanisms of the biological effects of EMP.

METHODS

T, TH and TS lymphocytes were estimated by acid phosphatase cytochemistry. Apoptotic lymphocytes and Bax and Bcl-2 proteins related to apoptosis were observed with in situ terminal labeling and immunocytochemistry.

RESULTS

Peripheral T lymphocyte subpopulations decreased obviously after EMP irradiation with (2-12) x 10(4) V/m. Apoptotic percentages of lymphocytes increased with the elevation of EMP doses. Ten days after different intensity radiation, the Bax protein was found to be elevated in accord with the peak value of lymphocyte apoptosis. However, Bcl-2 protein decreased obviously.

CONCLUSION

A definite field intensity EMP could induce injury to lymphocytes. Apoptosis induced by EMP is one of the main causes of peripheral lymphocyte death and leads to immunosuppression of the body. These results suggest that people should pay more attention to the injury caused by EMP, especially to the immunological functions of the body.

Soluble interleukin-6 receptor alpha inhibits the cytokine-Induced fractalkine/CX3CL1 expression in human vascular endothelial cells in culture

Soluble form of IL-6 receptor alpha (sIL-6R) is known to serve as an agonist, without exogenous IL-6, on endothelial cells which do not express IL-6R but have only IL-6 receptor beta chain, gp130. We investigated the effect of sIL-6R on fractalkine expression in human umbilical vein endothelial cells (HUVECs) in culture. sIL-6R markedly inhibited HUVEC fractalkine/CX3CL1 expression induced by interleukin (IL)-1alpha, tumor necrosis factor (TNF)-alpha, or interferon (IFN)-gamma. IL-1alpha-induced fractalkine expression was inhibited by sIL-6R in time- and concentration-dependent manners. The experiment using actinomycin D indicated that sIL-6R lowered the stability of fractalkine mRNA. The inhibitory effect of sIL-6R was reversed by anti-gp130 neutralizing antibody. sIL-6R inhibited adhesion of mononuclear cells (MNCs) to HUVEC monolayers stimulated with IFN-gamma, but it did not inhibit the adhesion to monolayers stimulated with IL-1alpha. MNC chemotactic activity of conditioned medium of HUVEC stimulated with IL-1alpha or IFN-gamma was inhibited by co-treatment with sIL-6R. sIL-6R may play a regulatory role in immune responses by modulating the interaction between leukocytes and the vascular endothelium.

[Studies on separation, purification and chemical structure of polysaccharide from Atractylodes macrocephala]

Separation and purification were done by column chromatographic fractionation; HPLC and 13C-NMR were used to determine the chemical structure of polysaccharide from Atractylodes macrocephala Koidz;, The molecular weight of the polysaccharide was estimated to be 1.36 x 10(5) (PSAM-1) and 1.04 x 10(5) (PSAM-2).

[Combined high dose chemotherapy with autologous stem cell transplantation and total body radiotherapy for 32 malignant lymphoma patients]

OBJECTIVE

To evaluate the effect of high dose chemotherapy with or without total body irradiation (TBI) supported by autologous hematopoietic stem cell transplantation (AHSCT) for malignant lymphoma.

METHODS

From June 1991 to April 2000, 32 malignant lymphoma (ML) patients were treated with AHSCT. Their ages ranged from 19 to 52 years (median 37). There were 23 non-Hodgkin's lymphoma (NHL) and 9 Hodgkin's lymphom (HD). Twelve patients received autologous bone marrow transplantation (ABMT) and 20 patients received autologous peripheral blood stem cell transplantation (APBSCT). In the latter, the mobilization plan was carboplatin and etoposide (CE) or CHOP (CTX, ADM, VCR, PDN) plus G/GM-CSF 10 micrograms/kg/d in high dose chemotherapy. BEAM (BCNU, Vp-16, AraC, MEL) or MEL 140 mg/m2 + Vp-16 200 mg + total body irradiation (TBI) 8 Gy.

RESULTS

Up to May 2000, hematopoietic reconstitution was reestabished in 100% (32/32) patients after AHSCT, with median follow-up of 1,020 days (40-3,240). The 1- and 2-year disease-free survivals (DFS) were 78.1%(25/32) and 46.9% (15/32) with the longest survival of 8 years. Even though eight patients have developed relapse, there is no transplantation-related death.

CONCLUSION

High dose chemotherapy and radiotherapy supported by autologous hematopoietic stem cell transplantation (AHSCT) for high risk, relapsed or sensitive ML, being highly efficient, should be the first indication. It is better than the standard conventional treatment. The hematopoietic reconstitution of autologous peripheral blood stem cell transplantation (APBSCT) is quicker than autologous bone marrow transplantation (ABMT). No significant difference between chemotherapy alone and chemotherapy plus total body irradiation is observed.

Predicted amino acid sequences for 100 JCV strains

DNA sequence variation between JCV genotypes is confined largely to noncoding intergenic regions and introns. Nevertheless, evidence suggests that the amino acid sequence variations among the 8 genotypes of JCV can influence the potential for neurovirulence of the virus. In the current study, the amino acid sequences for 100 JCV genomes were translated and grouped into genotype families. Subtype consensus sequences were determined and the type-specific amino acid sequence variants were identified.

Surface modification of neural recording electrodes with conducting polymer/biomolecule blends

The interface between micromachined neural microelectrodes and neural tissue plays an important role in chronic in vivo recording. Electrochemical polymerization was used to optimize the surface of the metal electrode sites. Electrically conductive polymers (polypyrrole) combined with biomolecules having cell adhesion functionality were deposited with great precision onto microelectrode sites of neural probes. The biomolecules used were a silk-like polymer having fibronectin fragments (SLPF) and nonapeptide CDPGYIGSR. The existence of protein polymers and peptides in the coatings was confirmed by reflective microfocusing Fourier transform infrared spectroscopy (FTIR). The morphology of the coating was rough and fuzzy, providing a high density of bioactive sites for interaction with neural cells. This high interfacial area also helped to lower the impedance of the electrode site and, consequently, to improve the signal transport. Impedance spectroscopy showed a lowered magnitude and phase of impedance around the biologically relevant frequency of 1 kHz. Cyclic voltammetry demonstrated the intrinsic redox reaction of the doped polypyrrole and the increased charge capacity of the coated electrodes. Rat glial cells and human neuroblastoma cells were seeded and cultured on neural probes with coated and uncoated electrodes. Glial cells appeared to attach better to polypyrrole/SLPF-coated electrodes than to uncoated gold electrodes. Neuroblastoma cells grew preferentially on and around the polypyrrole/CDPGYIGSR-coated electrode sites while the polypyrrole/CH(3)COO(-)-coated sites on the same probe did not show a preferential attraction to the cells. These results indicate that we can adjust the chemical composition, morphology, electronic transport, and bioactivity of polymer coatings on electrode surfaces on a multichannel micromachined neural probe by controlling electrochemical deposition conditions.

[Effects of phenytoin on structural aberration of human sperm chromosomes in vitro]

OBJECTIVE

To detect the mutagenic effects of phenytoin on human sperm chromosomes.

METHODS

The mutagenic effects of phenytoin at 10, 20 and 40 microgram/ml were tested by an in vitro testing system of human sperm chromosomes, with leomycin A5 as a positive control and mutagen-free solution as the blank control.

RESULTS

The frequencies of sperm with structural chromosomal aberrations and breakages of sperm chromosomes in the groups of 10 microgram/ml, 20 microgram/ml and 40 ug/ml of phenytoin were all higher than those in the blank control, but only in the group of 40 ug/ml, the elevated frequencies were statistically significant (P<0.005, P<0.05).

CONCLUSION

Phenytoin has probably mutagenic potential effect on human sperm cells.

Fusion of two novel genes, RBM15 and MKL1, in the t(1;22)(p13;q13) of acute megakaryoblastic leukemia

t(1;22) is the principal translocation of acute megakaryoblastic leukemias. Here we show this chromosomal rearrangement to result in the fusion of two novel genes, RNA-binding motif protein-15 (RBM15), an RNA recognition motif-encoding gene with homology to Drosophila spen, and Megakaryoblastic Leukemia-1 (MKL1), a gene encoding an SAP (SAF-A/B, Acinus and PIAS) DNA-binding domain.

Expression of p73 in colorectal carcinoma: clinicopathological relevance

p73 gene expression and its correlation with clinicopathological variables were examined in 92 patients (53 male, 39 female; age range 38 - 89 years) with colorectal carcinoma. Gene expression was determined by immunohistochemical analysis of resected formalin-fixed and paraffin-embedded carcinoma specimens. When p73 staining of each specimen was divided into two modes (small expression, 0-50% and large expression, > 50%), small expression of p73 was obtained in most cases. Tumour, grade, stage, site and size did not correlate with the mode of expression, but tumour recurrence differed according to mode. Expression of p73 was also related to prognosis: large expression indicated a shorter survival period. Our findings suggest that p73 expression plays a role in inducing tumour recurrence, and that analysis of the expression is useful in evaluating the clinical course of colorectal carcinoma post-surgery.

[Study on the application of quantitative analysis of cell-wall amino acids in actinomycetes classification]

This paper has collected 70 recognized type strains of actinomycete from home and abroad Microbiological culture collection centers. Adopting thin-layer chromatography and thin-layer chromatogram scanner methods to quantitatively analyze the composition of cell-wall amino acids in actinomycete. It has made comparison between quantitative results and qualitative ones. After a thorough discussion, a revision is made on the standard of dividing cell-wall types in actinomycete chemical classification, which has provided some original suggestion in hope of improving the research of actinomycete chemical classification.

A putative plant homolog of the yeast beta-1,3-glucan synthase subunit FKS1 from cotton (Gossypium hirsutum L.) fibers

A novel plant gene CFL1 was cloned from cotton (Gossypium hirsutum L.) fibers by expressed sequence tag (EST) database searching and 5'-RACE (rapid amplification of cDNA ends). This gene shows sequence homology with FKS1 which has been identified as the putative catalytic subunit of the yeast beta-1,3-glucan synthase. It encodes a protein (CFL1p) of 219 kDa with 13 deduced transmembrane helices and 2 large hydrophilic domains, one of which is at the N-terminus and the other in the internal region of the polypeptide. CFL1 displays 21% identity and 41% similarity to FKS1 at the amino acid level over its entire length, with 31% identity and 52% similarity for the hydrophilic central domain. Using RNA and protein blot analysis, CFL1 was found to be expressed at higher levels in cotton fibers during primary wall development. CFL1 also had a strong expression in young roots. Using a calmodulin (CaM)-gel overlay assay, the hydrophilic N-terminal domain of CFL1p was shown to bind to CaM, while the hydrophilic central domain did not. A putative CaM-binding domain, 16 amino acids long, was predicted in the hydrophilic N-terminal domain. Moreover, a product-entrapment assay demonstrated that a protein associated with an in vitro-synthesized callose pellet could be labeled by anti-CFL1 antibodies. Our finding suggests that CFL1 is a putative plant homolog of the yeast beta-1,3-glucan synthase subunit FKS1 and could be involved in callose synthesis.

Synergistic stimulation, by tumor necrosis factor-alpha and interferon-gamma, of fractalkine expression in human astrocytes

Fractalkine is a CX3C chemonkine that appears to be a neuron-to-microglia signal molecule in the central nervous system. We studied the expression of fractalkine in normal human astrocytes in culture, by using semi-quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. We found that tumor-necrosis factor alpha (TNF-alpha) and interferon-gamma (IFN-gamma) synergistically enhance the expression of fractalkine. The expression of both fractalkine mRNA and protein was increased in time- and concentration-dependent manners in the cells co-stimulated with TNF-alpha and IFN-gamma. Cycloheximide, an inhibitor of protein synthesis, and dexamethasone had no effect on the synergy of the stimulation of fractalkine expression. We conclude that normal human astrocytes produce fractalkine by co-stimulation with pro-inflammatory cytokines and it may serve as a potential signal for immune and inflammatory responses in the central nervous system.

[Effects of free radicals and amyloid beta protein on the currents of expressed rat receptors in Xenopus oocytes]

AIM

To investigate the effects of free radicals (FRs) and amyloid beta protein (A beta 1-40) on the functions of expressed neurotransmitter receptors (NRs) from rat brains in Xenopus oocytes.

METHODS

Total RNA and Messenger RNA (mRNA) was prepared from 3-month-old Wistar rat brain tissues with Promega kits and microinjected into mature Xenopus oocytes (stage V - VI) with 50 nl (50 ng) for each oocyte for receptor expression and their currents were recorded with double electrode voltage clamp technique. Superoxide anion free radicals (SAFRs) and A beta 1-40 was added 12 h, 24 h, 96 h to incubation solution before recording.

RESULTS

The results showed that oocytes expressed mACh, glutamate, dopamine, serotonin and gamma-aminobutyric acid receptors. The current characteristics of these receptors were inward currents carried by chloride ion with their equilibrium potentials close to - 22 mV. A beta 1-40 and free radicals had a kind of inhibitory effect on the expressed GluR. When treated with 60 nmol/L A beta 1-40 over 24 h, the currents of GluR significantly decreased (25% off, P < :0.01). When oocytes were co-treated with 60 nmol/L A beta 1-40 and SAFRs over a period of 12 h, the currents of glutamate receptor significantly decreased (21% of P < 0.05), and the decreased percentage reached 52% over 24h co-treated with 60 nmol/L A beta 1-40 and SAFRs. Vitamin E had partial antagonistic effect against these effects.

CONCLUSION

The result suggests that A beta has a kind of inhibitory effects upon glutamate receptor, which is similar to those of free radicals. Their effects can be antagonized by vitamin E. This implies that A beta may play roles via inhibiting receptor function in pathophysiology of Alzheimer's disease.

Mitochondrial aldehyde dehydrogenase activity is required for male fertility in maize

Some plant cytoplasms express novel mitochondrial genes that cause male sterility. Nuclear genes that disrupt the accumulation of the corresponding mitochondrial gene products can restore fertility to such plants. The Texas (T) cytoplasm mitochondrial genome of maize expresses a novel protein, URF13, which is necessary for T cytoplasm-induced male sterility. Working in concert, functional alleles of two nuclear genes, rf1 and rf2, can restore fertility to T cytoplasm plants. Rf1 alleles, but not Rf2 alleles, reduce the accumulation of URF13. Hence, Rf2 differs from typical nuclear restorers in that it does not alter the accumulation of the mitochondrial protein necessary for T cytoplasm-induced male sterility. This study established that the rf2 gene encodes a soluble protein that accumulates in the mitochondrial matrix. Three independent lines of evidence establish that the RF2 protein is an aldehyde dehydrogenase (ALDH). The finding that T cytoplasm plants that are homozygous for the rf2-R213 allele are male sterile but accumulate normal amounts of RF2 protein that lacks normal mitochondrial (mt) ALDH activity provides strong evidence that rf2-encoded mtALDH activity is required to restore male fertility to T cytoplasm maize. Detailed genetic analyses have established that the rf2 gene also is required for anther development in normal cytoplasm maize. Hence, it appears that the rf2 gene was recruited recently to function as a nuclear restorer. ALDHs typically have very broad substrate specificities. Indeed, the RF2 protein is capable of oxidizing at least three aldehydes. Hence, the specific metabolic pathway(s) within which the rf2-encoded mtALDH acts remains to be discovered.

[Inhibitory effect of antisense VEGF₁₂₁ and endostatin genes transfection on tumor growth and metastasis of human giant cell lung cancer]

BACKGROUND

To explore the co-operative inhibitory effect of antisense VEGF gene and endostatin gene transfection on tumor angiogenesis, tumor growth and metastasis of lung cancer.

METHODS

Antisense VEGF₁₂₁ cDNA was transfected into PG cells(PG-AS-VEGF) by lipofectin. After PG-AS-VEGF cells were xenografted to nude mice, PsectagA-endostatin gene was transfected into nude mice by electric pulse mediation. The MVDs in tumors and tumor biological characteristics were observed.

RESULTS

(1)The MVD in PG-AS-VEGF tumor in nude mice was significantly lower than that in PG-vector tumor (PG-AS-VEGF and PG-vector: 40.67±9.35 and 58.34±10.52, respectively) in nude mice. (2)There was no significant difference between the PG-vector tumor and PG-AS-VEGF tumor in early stage of the tumor growth in vivo. However, PG-AS-VEGF tumor grew significantly more slowly than PG-vector tumor after 18 days (P<0.05). (3)PG-AS-VEGF tumor could lead to regional and/or distant lymph node metastases (16.7%, 2/12), which was much more infrequent than that in PG-vector group (50%, 6/12). (4) PG-AS-VEGF tumor growth was remarkably inhibited by endostatin gene transfected at site of the tumor inoculation as compared with the control group in nude mice (P<0.05). (5)The PG-AS-VEGF tumors transfected with the endostatin gene at site of the tumor inoculation(AST) could also produce much lower regional and/or distant lymph node metastases rate (12.5%, 1/8) than that in the PG-AS-VEGF tumor transfected with the PsectagA vector (ASP)(75%, 6/8).

CONCLUSIONS

Endostatin gene transfection could cooperatively inhibit the growth and spontaneous lymph node metastasis of antisense VEGF gene transfected PG cells in nude mice.

[Study on the growth of H1299 cell line transfected transiently with mouse p53 minigenes with different codon 172 structures]

BACKGROUND

To investigate the effect on cell growth after transfected with mouse 172 wild-type p53 (Arg), pseudo-wild-type p53 (Arg->Leu) and mutant p53 (Arg->His).

METHODS

Vectors of three kinds of p53 minigene were transfected into p53-null H1299 cells through lipofectAMINE. Cells were collected at different time after transfection and analyzed by cell counting, flow cytometry and Western blotting.

RESULTS

Wild-type p53 and pseudo-wild-type p53 could induce cell apoptosis and cell cycle arrest at different time. Bax, p21(WAF1) and Mdm-2 were transactivated by wild-type p53 and pseudo-wild-type p53. No tumor growth suppression was observed in mutant p53 transfected cells.

CONCLUSIONS

Wild-type p53 and pseudo-wild-type p53 can inhibit cell growth by inducing apoptosis and cell cycle arrest through transactivation of Bax and p21(WAF1). There exists feedback loop between Mdm-2 and p53. The different biological effect between 172Leu and 172His shows that some p53 variants such as 172 Arg->Leu may act as wild-type p53.

Multiplex genotype analysis of invasive carcinoma and accompanying proliferative lesions microdissected from breast tissue

To understand the genetic basis of breast cancer in a comprehensive way, purported precursor lesions need to be analyzed at a large number of genetic marker loci and compared with each other and with the invasive components. However, the microscopic size of most of these lesions and the very small amount of material that can be obtained through microdissection limit the number of loci that can be included in the analysis. To address this issue, a multiplex genotyping approach has been developed. With this approach, polymorphic sequences at 28 marker loci were amplified simultaneously from the micro-dissected components in 5-microm paraffin-embedded breast tissue sections. The genotypes of the lesions were determined after resolving the amplified allelic products by denaturing gradient gel electrophoresis. Because the material isolated from each lesion in a single 5-microm section was sufficient for several 28-locus assays and several successive tissue sections with the same set of lesions may be prepared, it is possible to determine the genotype of each lesion at hundreds of genetic marker loci that may well cover the human genome. Analyzing a sufficient number of cases may yield information that could be used to understand the genetic basis of breast cancer development in a comprehensive way.

Ecto-ATPase mRNA is regulated by FSH in Sertoli cells

A putative messenger RNA (mRNA) sequence, designated C8, that was up-regulated in Sertoli cells prepared from hypophysectomized rats treated with testosterone, was isolated from a Sertoli cell complementary DNA (cDNA) library. The coding region of C8 exhibited 99% identity with rat brain ecto-ATPase and expressed a 60-kilodalton protein following in vitro transcription/translation. Transfection of COS7 cells with C8 cDNA resulted in a marked increase in Ca2+- and Mg2+-dependent ATPase activity in both whole cells and cell homogenates, which is consistent with localization of this enzyme in the plasma membrane. C8 ecto-ATPase steady state mRNA levels were increased within 6 hours and for 3 day, by follicle-stimulating hormone (FSH) in Sertoli cells but not in peritubular cells. In contrast, dibutyryl-cyclic adenosine monophosphate (cAMP) increased ecto-ATPase in both Sertoli and peritubular cells. Testosterone had no significant effect under these conditions. These data indicate that ecto-ATPase mRNA is positively regulated by FSH in Sertoli cells and by cAMP in both Sertoli and peritubular cells. This enzyme may play a role in the control of extracellular signaling by ATP, adenosine, or both in the cells of the seminiferous epithelium.

A risk factor index predicting adolescent cigarette smoking: a 7-year longitudinal study

The authors used longitudinal data to develop a risk factor index (RFI) for the prediction of smoking behavior in youth. Students were followed yearly from 6th through 12th grades in a prospective longitudinal study. Ten risk factors were identified and combined into an RFI. Data were analyzed with a generalized estimating equations approach. The RFI predicted both concurrent smoking and use of cigarettes in the succeeding year. It further predicted whether a youth would smoke at any point during his or her school career. Prediction was better for boys than for girls. Furthermore, the RFI better predicted heavy smoking than any use of cigarettes. The RFI could be useful in selecting youth for intensive prevention and early intervention efforts. Results also suggest the importance of further examination of gender differences in smoking behavior.

Effects of free radicals and amyloid beta protein on the currents of expressed rat receptors in Xenopus oocytes

OBJECTIVE

To investigate the effects of free radicals (FRs) and amyloid beta protein 1-40 (A beta 1-40) on the functions of expressed neurotransmitter receptors (NRs) in Xenopus oocytes.

METHODS

Total RNA and messenger RNA (mRNA) was prepared from 3-month-old Wistar rat brain tissues with Promega kits and microinjected into maturated Xenopus oocytes (stages V-VI) with 50 nl (50 ng) for each oocyte. The microinjected oocytes were incubated with modified Bath's solution at 19.0 degrees C +/- 1.0 degree C for receptor expression and their currents were recorded with double electrode voltage clamp technique. Superoxide anion free radicals (SAFRs) were produced via a reaction system (HPX/XO) with hypoxanthine (HPX, 0.05 mol/L) and xanthine oxidase (XO, 0.1 U/L). In order to observe the effects of A beta and SAFRs on the expressed glutamate receptor, HPX/XO and A beta 1-40 were added to incubation solution at 12 h, 24 h and 96 h before recording.

RESULTS

The results showed that the oocytes expressed functional NRs originating from rat brain tissues. These NRs included muscarinic acetylcholine (mACh), glutamate (Glu), dopamine (DA), serotonin (5-HT) and gamma-aminobutyric acid (GABA). The current characteristics of expressed receptors were inward currents carried by chloride ion with their equibrilium potentials close to -22 mV. The extent of effect on the current of expressed glutamate receptor from rat brain was different among different A beta concentrations and incubation times. A beta 1-40 at a concentration of 20 nmol/L had little effect on the currents of expressed rat brain glutamate receptors up to 24 h of incubation period; but the currents of glutamate receptor were significantly decreased (25% off, P < 0.01) in the treatment of 60 nmol/L A beta 1-40 over 24 h. Moreover, when 20 nmol/L A beta 1-40 was co-incubated over 12 h with SAFRs produced by the reaction system of HPX/XO, it was found that the currents of expressed rat brain glutamate receptors had been changed markedly. When the oocytes were co-treated with 60 nmol/L A beta 1-40 and SAFRs over a period of 12 h, the currents of glutamate receptor significantly decreased (21% off, P < 0.05), and the decreased percentage reached 52% over 24 h co-treatment with 60 nmol/L A beta 1-40 and SAFRs. In addition, vitamin E had a partial effect against this inhibitory effect.

CONCLUSION

The results suggest that A beta has a kind of inhibitory effect upon the current of the glutamate receptor, similar to the effects of free radicals. The effects can be antagonized by vitamin E. These imply that A beta may play a role via inhibiting receptor function in the pathophysiology of Alzheimer's disease.

Effects of Lu-Duo-Wei capsules on superoxide dismutase activity and contents of malondialdehyde and lipofuscin in the brain of the housefly

The biochemical actions of Lu-Duo-Wei capsules and tea polyphenol in relation to their antioxidant capability have been compared in the male housefly, Musca domestica. It was found that tea polyphenol had the effect of increasing the activity of superoxide dismutase (SOD) in the brain of the housefly only at the 60th day in the experimental period whereas Lu-Duo-Wei showed more obvious effects on SOD than tea polyphenol irrespective of experimental days. Moreover, the contents of malondialdehyde (MDA) and the rate of lipofuscin accumulation were decreased by the effect of Lu-Duo-Wei at the 20th, 40th, 50th and 60th days, while the similar effect of tea polyphenol on the content of MDA and lipofuscin was observed only at the 40th day. These results indicated that the biochemical actions of Lu-Duo-Wei in antiaging was much stronger than those of tea polyphenol, the mechanism of which was probably related to the synergistic effect of its involved antioxidants and others as well as the exclusive promotion of SOD biosynthesis/or a reduction of free radical-induced damage of the enzyme.

Desferrioxamine, an iron chelator, upregulates cyclooxygenase-2 expression and prostaglandin production in a human macrophage cell line

Prostaglandins (PGs) play regulatory roles in a variety of physiological and pathological processes, including the immune response, cytoprotection and inflammation. Desferrioxamine (DFX), an iron chelator, is known to reduce free radical-mediated cell injury and to upregulate certain inflammatory mediators. We investigated the effects of DFX on the production of PGs and the expression of cyclooxygenase-2 (COX-2), the rate-limiting enzyme in the synthesis of PGs, using a human macrophage cell line, U937. Our results showed that COX-2 expression and PGE(2) production are upregulated by DFX treatment and that this upregulation is dependent on both COX-2 promoter activity and alteration of mRNA stability. COX-2 promoter activity may be, at least in part, mediated by activation of the extracellular signal-regulated kinase pathway. These findings suggest that iron metabolism may regulate inflammatory processes by modulating PGs as well as other inflammatory mediators.

Molecular cloning and regulation of expression of two novel mouse CYP4F genes: expression in peroxisome proliferator-activated receptor alpha-deficient mice upon lipopolysaccharide and clofibrate challenges

Cytochrome P450 4F isoforms catalyze the hydroxylation of eicosanoids such as leukotriene B(4), prostaglandins, and lipoxins as well as hydroxyeicosatetraenoic acids. In the present study, we report the molecular cloning of two novel mouse CYP4F isoforms, CYP4F15 and CYP4F16. Sequence comparison showed that CYP4F15 has 93.5% homology to CYP4F4 and CYP4F16 has 90.8% homology to CYP4F5, therefore they are the orthologs for rat CYP4F4 and CYP4F5, respectively. Both isoforms are expressed in liver and also in extrahepatic tissues but the patterns of expression are slightly different. To elucidate further the regulation and regulatory mechanism of the two isoforms, renal and hepatic CYP4F15 and CYP4F16 expression were analyzed using wild-type (SV/129) mice and peroxisome proliferator-activated receptor (PPAR) alpha null mice with or without challenge by bacterial endotoxin (LPS) or clofibrate. Renal expression of CYP4F15 was induced by LPS and clofibrate in (+/+) mice, and these effects were absent in the (-/-) mice. Renal expression of CYP4F16 was not affected by LPS or clofibrate in (+/+) or (-/-) mice. In contrast, hepatic expression of CYP4F15 and CYP4F16 was significantly reduced by LPS-treatment in (+/+) mice. A lesser reduction was also seen in the (-/-) mice, suggesting that PPARalpha is partially responsible for this down-regulation. Clofibrate treatment caused the reduction of hepatic CYP4F16 expression and this effect was not dependent on PPARalpha. Clofibrate treatment had no effect on hepatic CYP4F15 expression. Together, our data indicate that CYP4Fs are regulated in an isoform-specific, tissue-specific, and species-specific manner.

Microencapsulated bovine chromaffin cell xenografts into hemiparkinsonian rats: a drug-induced rotational behavior and histological changes analysis

Bovine chromaffin cells were microencapsulated within alginate-polylysine-alginate (APA) membranes. Microencapsulated bovine chromaffin cells as well as unencapsulated cells and empty microcapsules were grafted into the brain of hemiparkinsonian rats with 6-hydroxydopamine (6-OHDA) lesions. Apomorphine-induced rotational behavior of the host animals and the survival of the grafted chromaffin cells were examined after transplantation. The animals receiving microencapsulated bovine chromaffin cells showed a significant decrease (17.6--35.6%) in apomorphine-induced rotation 1 week postimplantation that remained stable for the 10 month test period. Fluorescent histochemistry further revealed that microencapsulation increased the chromaffin cell survival with only a minimum host reaction for up to 10 months posttransplantation while the survival of free, unencapsulated chromaffin cells was only modest and was accompanied by a large inflammatory response. The reduction of apomorphine-induced rotations was correlated with the survival of bovine chromaffin cells in the host brain. The data indicate that encapsulation of bovine chromaffin cells in APA membranes reduces the host immune response to the xenograft and prolongs the viability of the grafted cells.

[Study of the growth and secretion of microencapsulated pancreatic B cell line in vitro]

AIM

To study the growth and secretion of pancreatic B cell line BTC6-F7 in the alginate polylysine-alginate (APA) microcapsules and explore the possibility of utilizing it as bioartificial islets.

METHODS

Microencapsulated BTC6-F7 cells prepared with electric droplet generator were cultured in vitro, and the growth and insulin secretion of them were measured periodically.

RESULTS

Over the 90-day observation period, BTC6-F7 cells were able to grow and survive as cell clusters in the microcapsules and finally fulfill the capsules. But the microcapsules remained well after the long-time culture. The average total cell number per capsule were increasing with time, but the cell viability was decreasing. The changes of insulin secretion and average live cell number per capsule were in a same manner: for the first two weeks they increased rapidly and then maintained in a relatively constant levels for the rest time.

CONCLUSION

The microencapsulated pancreatic B cells prepared by us could survive, grow and secretion for a long time. This has made a basis for further development of bioartificial islets, and also can be used to study the mechanism and therapy of diabetes mellitus.

Identification of metastasis associated gene G3BP by differential display in human cancer cell sublines with different metastatic potentials G3BP as highly expressed in non-metastatic

OBJECTIVE

To investigate genes involved in cancer metastasis, mRNA differential display was used to compare the levels of gene expression in two cell sublines derived from human giant cell carcinoma of lung (PG) which had different metastatic potentials.

METHODS

Using in vivo tumorigenicity and a spontaneous metastasis assay in nude mice, two sublines (BE1, LH7) from human giant cell carcinoma of lung (PG) with different metastatic potentials were isolated and characterized. mRNA differential display was used to compare the levels of gene expression between them and the obtained results were confirmed by Northern hybridization.

RESULTS

One differentially expressed band was nearly identical (99% homology) to Ras-GTPase-Activating protein SH3 domain binding protein (G3BP). G3BP displayed a strong expression in LH7 (non-metastatic in recipient nude mice) and a very weak expression in BE1 (100% metastatic frequency). The same different expression level of G3BP was detected in Northern hybridization with another panel of cell sublines with different metastatic potentials (established in our lab) derived from human prostate carcinoma cell line PC-3M.

CONCLUSION

Our results indicate that G3BP was implicated in cancer metastasis because of its differential expressions in the two panels of cell sublines with different metastatic potentials.

Lipopolysaccharide induces the expression of cellular inhibitor of apoptosis protein-2 in human macrophages

Apoptosis is an important process in normal animal development as well as in diseases, and inhibitor of apoptosis protein (IAP) is one of the important factors that regulate apoptotic cell death. We found that lipopolysaccharide (LPS) enhances the expression of mRNA and protein of cellular IAP-2 (cIAP2) in human monoblastic U937 cells differentiated by phorbol ester pretreatment. cIAP2 mRNA was not detected in undifferentiated U937 cells. mRNAs of cIAP1 and X-chromosome-linked IAP (XIAP) were expressed constitutively and not affected by LPS in both undifferentiated and differentiated cells. LPS stimulated the expression of cIAP2 mRNA and protein in time- and concentration-dependent manners. LPS enhanced the expression of cIAP2 mRNA and protein in human monocyte-derived macrophages, which was associated with the inhibition of the caspase-3 activation, i.e., decrease in active p17 fragment of caspase-3 with simultaneous accumulation of precursor p20 fragment. We conclude that LPS may inhibit apoptosis of macrophages, at least in part, through the induction of cIAP2.

Distinct roles for L- and T-type Ca(2+) channels in regulation of atrial ANP release

Atrial secretion of atrial natriuretic peptide (ANP) has been shown to be regulated by atrial workload. Although modulating factors for the secretion of ANP have been reported, the role for intracellular Ca(2+) on the secretion of ANP has been controversial. The purpose of the present study was to define roles for L- and T-type Ca(2+) channels in the regulation of ANP secretion in perfused beating rabbit atria. BAY K 8644 (BAY K) increased atrial stroke volume and pulse pressure. BAY K suppressed ANP secretion and ANP concentration in terms of extracellular fluid (ECF) translocation concomitantly with an increase in atrial dynamics. BAY K shifted the relationship between ANP secretion and ECF translocation downward and rightward. These results indicate that BAY K inhibits myocytic release of ANP. In the continuous presence of BAY K, diltiazem reversed the effects of BAY K. Diltiazem alone increased ANP secretion and ANP concentration along with a decrease in atrial dynamics. Diltiazem shifted relationships between ANP secretion and atrial stroke volume or ECF translocation leftward. The T-type Ca(2+) channel inhibitor mibefradil decreased atrial dynamics. Mibefradil inhibited ANP secretion and ANP concentration in contrast with the L-type Ca(2+) channel inhibitor. These results suggest that activation of L- and T-type Ca(2+) channels elicits opposite effects on atrial myocytic release of ANP.

Prevention of graft-versus-host disease by a novel immunosuppressant, PG490-88, through inhibition of alloreactive T cell expansion

BACKGROUND

PG490-88 is a water soluble, semisynthetic derivative of a novel compound PG490 (triptolide) purified from the Chinese herb Tripterygium Wilfordii Hook F.

METHODS

PG490-88 was administrated into recipient mice in a model (B10.D2-->BALB/c) of lethal graft-versus-host disease (GVHD) to study the effects of PG490-88 on GVHD and on the various steps involved in the pathological course of GVHD.

RESULTS

Injection of PG490-88 i.p. at a dose of 0.535 mg/kg/day for the first 3 weeks after transplantation protected all the recipients from developing GVHD up to 100 days after transplantation. PG490-88 inhibited in vivo both CD4+Vbeta3+ and CD8+Vbeta3+ T cell (alloreactive T cells in this model) expansion in the spleen by 64.09 and 34.02%, respectively, at the time when Vbeta3+ cell expansion was in the logarithmic phase (day 3 after transplantation). Intracellular cytokine staining without further in vitro activation demonstrated 47.42% inhibition of IL-2 production among CD4+ spleen cells in PG490-88-treated mice as compared to GVHD control on day 3 after transplantation. In contrast, CD25 (alpha chain of interleukin-2 receptor) expression did not differ.

CONCLUSIONS

PG490-88 is highly effective in prevention of murine GVHD. The immunosuppressive effect of PG490-88 is mediated by inhibition of alloreactive T cell expansion through interleukin-2 production.

Gene delivery from a DNA controlled-release stent in porcine coronary arteries

Expandable intra-arterial stents are widely used for treating coronary disease. We hypothesized that local gene delivery could be achieved with the controlled release of DNA from a polymer coating on an expandable stent. Our paper reports the first successful transfection in vivo using a DNA controlled-release stent. Green fluorescent protein (GFP) plasmid DNA within emulsion-coated stents was efficiently expressed in cell cultures (7.9% +/- 0.7% vs. 0.6% +/- 0.2% control, p < 0.001) of rat aortic smooth muscle cells. In a series of pig stent-angioplasty studies, GFP expression was observed in all coronary arteries (normal, nondiseased) in the DNA-treated group, but not in control arteries. GFP plasmid DNA in the arterial wall was confirmed by PCR, and GFP presence in the pig coronaries was confirmed by immunohistochemistry. Thus, DNA-eluting stents are capable of arterial transfection, and could be useful as delivery systems for candidate vectors for gene therapy of cardiovascular diseases.