An ontology for the integration of multiple genetic disorder data sources

As a huge amount of gene disorder information is available on the Internet, there is an increasing requirement to integrate these data sources. The integration of gene disorder data sources provides an important tool in the research of life science, therapeutics, and genetic disease prevention and inhibition. The key challenge of such integration is how to deal with semantic heterogeneity of multiple information resources. The paper proposes an ontology-based approach to describe and extract the semantics of genetic disorder terminologies and provides a mechanism for sharing and reusing genetic disorder knowledge. According to this unified meta model, heterogeneous gene disorder data sources can be integrated, and a semantic middleware has the ability to do reasoning on the knowledge base of gene disorder for users and applications' various queries.

Blockade of RAGE suppresses alloimmune reactions in vitro and delays allograft rejection in murine heart transplantation

The receptor for advanced glycation endproducts (RAGE), a multiligand member of the immunoglobulin superfamily, interacts with proinflammatory AGEs, the products of nonenzymatic glycation and oxidation of proteins; high-mobility group box 1 (HMGB1), also known as amphoterin and S100/calgranulins to amplify inflammation and tissue injury. Previous studies showed that blockade of RAGE suppressed recruitment of proinflammatory mechanisms in murine models. We tested the hypothesis that RAGE contributes to alloimmune responses and report that in vivo, acute rejection of fully allogeneic cardiac allografts in a murine model of heterotopic cardiac transplantation is significantly delayed by pharmacological antagonism of RAGE. In parallel, allogeneic T-cell proliferation in the mixed lymphocyte reaction is, at least in part, RAGE-dependent. These data provide the first insights into key roles for RAGE in allorecognition responses and suggest that antagonism of this receptor may exert beneficial effects in allogeneic organ transplantation.

Cloning of a cDNA encoding the Saussurea medusa chalcone isomerase and its expression in transgenic tobacco

Chalcone isomerase (CHI; EC 5.5.1.6) is a key enzyme in the flavonoid biosynthesis pathway. We isolated a CHI gene (SmCHI) from a cDNA library derived from Saussurea medusa (Asteraceae) cell cultures. The cDNA and genomic sequences of SmCHI are the same; in other words, this gene is intronless. The coding region of the gene is 699 bp long, and its deduced protein consists of 232 amino acids with a predicted molecular mass of 24 kDa and a pI of 4.7. The deduced amino acid sequence of SmCHI shares 79.3% identity with CHI from Callistephus chinensis, a familial relative to S. medusa; this homology is higher than those with CHI's from any other plant species. A functional bioassay for SmCHI was performed by transforming Nicotiana tabacum plants in the sense or antisense orientation under the regulation of the cauliflower mosaic virus (CaMV) 35S promoter. Transgenic tobacco plants overexpressing sense SmCHI produced up to fivefold total flavonoids over wild-type tobacco plants, mainly due to an enhanced accumulation of rutin. Transgenic tobacco plants with antisense SmCHI accumulated smaller amounts of flavonoids; this is apparently brought about by suppressed expression of the endogenous CHI gene. CHI activities also positively correlated with the amounts of total flavonoids accumulated in the transgenic plants. It is concluded that overexpression of SmCHI can be used as a useful approach to increase flavonoid production in transgenic plants.

Modeling biodegradation of toluene in rotating drum biofilter

Rotating drum biofilters (RDBs) are cost-effective for control of emissions of volatile organic compounds (VOCs) from waste gas streams. In this paper, a dynamic mathematical model is presented which simulates and predicts the variation in performance of a multi-layer RDB with time on the basis of the two-film theory. The model takes into account factors including biofilm growth and biomass loss, and a changing biofilm surface area and thickness assuming quasi-steady-state conditions in the two-phase system and uniform bacterial population. Toluene was assumed to be the only rate-limiting substrate. The model equations for the gas-phase mass balance and biofilm growth were solved using MATLAB based on the fourth-fifth-order Runge-Kutta technique, and the concentration profiles in the biofilms were obtained using the method of orthogonal collocation. Simulation results showed that the toluene removal efficiency decreased with increased toluene loading or increased duration of operation of the biofilter. Calculation results were compared to the experimental results, which demonstrated that the dynamic model provided a good simulation of the performance of the biofilter.

Effects of phenobarbital on metabolism and toxicity of diclofenac sodium in rat hepatocytes in vitro

Diclofenac sodium (DF-Na) was a nonsteroidal anti-inflammatory drug used in various aspects of inflammatory disease. The purpose of this study was to examine the effects of phenobarbital (PB) on metabolism and toxicity of DF-Na in vitro and explore the potential mechanism of DF-Na induced hepatotoxicity. Rat hepatocytes were isolated by a modification of the two-step in situ collagenase perfusion technique and the harvested rat hepatocytes were cultured with sandwich method. Control or PB (2 mM) pre-treated hepatocytes were incubated with DF-Na (0.1, 0.05 or 0.01 mM) in vitro and cytosolic enzyme leakage levels, cytochrome P450 (CYP) 3A activity, and metabolite content of DF-Na in cell culture medium were measured. The results showed that without any treatment hepatocyte CYP 3A activity gradually decreased with culture time. On day four, CYP 3A activity was 53% of the initial value. The decline of CYP 3A was partially reversed by CYP inducer PB, and the maximum induction of CYP 3A was 2.2-fold over control after continuous exposure of hepatocytes to 2 mM PB for 48 h. Lactic dehydrogenase (LDH), aspartate transaminase (AST), and alanine transamine (ALT) activity and the contents of the DF-Na metabolites 4'-hydroxydiclofenac (4'-OH-DF) and 5-hydroxydiclofenac (5-OH-DF) in media appeared to increase with increasing DF-Na concentrations, though there were no significant differences between DF-Na exposed and control hepatocytes. However, if the hepatocytes first were pre-treated with 2 mM PB for 2 days and then exposed to DF-Na, the concentrations of DF-Na metabolites and the activity of LDH in the media were significantly higher than that of control group. These findings suggest that the hepatotoxicity and metabolism of DF-Na in rat hepatocytes are increased when hepatic CYP 3A activity is increased.

Synergistic action of advanced glycation end products and endogenous nitric oxide leads to neuronal apoptosis in vitro: a new insight into selective nitrergic neuropathy in diabetes

AIMS/HYPOTHESIS

We have previously shown that in diabetes nitrergic neurones innervating the urogenital and gastrointestinal organs undergo a selective degenerative process. This comprises an initial insulin-reversible decrease in neuronal nitric oxide synthase (nNOS) in the axons, followed by apoptosis of the nitrergic neurones, a process that is not reversible by insulin. Since apoptosis was independent of serum glucose concentrations, and advanced glycation endproducts (AGEs) have been implicated in the pathogenesis of diabetic complications, we have now measured AGEs in the serum and penis, pyloric sphincter and pelvic ganglia of diabetic animals at different times after streptozotocin treatment. Furthermore, we have studied their effect in vitro on human neuroblastoma (SH-SY5Y) cells in the presence or absence of nNOS expression.

METHODS

Serum AGEs were measured using fluorometry and ELISA. Accumulation of AGEs in the tissues was evaluated with immunohistochemistry. The viability, apoptosis and oxidative stress in SH-SY5Y cells were measured upon exposure to AGEs or high concentrations of glucose.

RESULTS

AGEs increased gradually in the serum and tissues of streptozotocin-induced diabetic rats; this process was not affected by delayed insulin treatment. In SH-SY5Y cells, AGEs, but not high glucose concentrations, increased the reactive oxygen species and caspase-3-dependent apoptosis in a synergistic fashion with endogenous nitric oxide (NO). Apoptosis was prevented by treatment with a NOS inhibitor, a pan-caspase inhibitor, a soluble receptor of AGEs or an anti-oxidant, but not an inhibitor of soluble guanylate cyclase.

CONCLUSIONS/INTERPRETATION

The synergistic actions of NO and AGEs account for the irreversible nitrergic degeneration in diabetes.

Effect of aggregate size in cell cultures of Saussurea medusa on cell growth and jaceosidin production

Cell suspension cultures of Saussurea medusa were grown in shake flasks and a 5-l stirred tank bioreactor. Biomass and jaceosidin distribution in cell aggregates of different sizes were investigated during the cultivation period. The results showed that on day 10, jaceosidin accumulation showed an increase with increasing size of the cell aggregate to 4 mm in diameter, with the highest jaceosidin accumulation being 12.2 mg/g. An inverse tendency was observed with cell aggregates larger than 4 mm in diameter, with the lowest accumulation being 3.1 mg/g. However, all of the cell aggregates, despite their size, synthesized almost the same amount of jaceosidin at day 12. Oxygen diffusion limitation and cell-cell contact may explain this behavior. In comparison with cells cultivated in shake flasks, decreased biomass and decreased jaceosidin concentration were observed when the cells were cultivated in a stirred tank bioreactor. The sublytic effects caused by the hydrodynamic stress in combination with insufficient nutrients in the bioreactor may cause cell damage.

RAGE and arthritis: the G82S polymorphism amplifies the inflammatory response

The receptor for advanced glycation end products (RAGE) and its proinflammatory S100/calgranulin ligands are enriched in joints of subjects with rheumatoid arthritis (RA) and amplify the immune/inflammatory response. In a model of inflammatory arthritis, blockade of RAGE in mice immunized and challenged with bovine type II collagen suppressed clinical and histologic evidence of arthritis, in parallel with diminished levels of TNF-alpha, IL-6, and matrix metalloproteinases (MMP) 3, 9 and 13 in affected tissues. Allelic variation within key domains of RAGE may influence these proinflammatory mechanisms, thereby predisposing individuals to heightened inflammatory responses. A polymorphism of the RAGE gene within the ligand-binding domain of the receptor has been identified, consisting of a glycine to serine change at position 82. Cells bearing the RAGE 82S allele displayed enhanced binding and cytokine/MMP generation following ligation by a prototypic S100/calgranulin compared with cells expressing the RAGE 82G allele. In human subjects, a case-control study demonstrated an increased prevalence of the 82S allele in patients with RA compared with control subjects. These data suggest that RAGE 82S upregulates the inflammatory response upon engagement of S100/calgranulins, and, thereby, may contribute to enhanced proinflammatory mechanisms in immune/inflammatory diseases.

Heavy metal contents in the Delft canal sediments and suspended solids of the River Rhine: multivariate analysis for source tracing

We have analyzed heavy metal contents in the sediments of three Delft inner city canals (Rietveld, Oude Delft and Zuiderstraat) and compared them with the heavy metal contents in the River Rhine suspended solids. All the data were examined by multivariate analysis in order to explain the behavior and sources of each metal. Correlation coefficient matrices were studied in order to find an internal structure and assist in identification of pollutant sources. The good correlation among almost all the heavy metals (except Pb) indicates that there are common sources or at least one major source for them. Based on the factor analysis technique, principal components score plots were obtained to cluster the data (63 samples from the Delft canals and 10 from the River Rhine) and describe their different characteristics. It was found in the plots that the data from the River Rhine clustered together with 2 out of the 3 Delft stations (Rietveld, Oude Delft). This supports the view that the River Rhine is an important external micropollutant source for the Delft inner city canals. The third station (Zuiderstraat) showed much higher pollution levels than the other Delft canals; apparently it has been influenced not only by the River Rhine but also by internal pollutant inputs such as metal corrosion and paints from local boathouses.

Sequence analysis of four Shigella boydii O-antigen loci: implication for Escherichia coli and Shigella relationships

Shigella strains are in reality clones of Escherichia coli and are believed to have emerged relatively recently (G. M. Pupo, R. Lan, and P. R. Reeves, Proc. Natl. Acad. Sci. USA 97:10567-10572, 2000). There are 33 O-antigen forms in these Shigella clones, of which 12 are identical to O antigens of other E. coli strains. We sequenced O-antigen gene clusters from Shigella boydii serotypes 4, 5, 6, and 9 and also studied the O53- and O79-antigen gene clusters of E. coli, encoding O antigens identical to those of S. boydii serotype 4 and S. boydii serotype 5, respectively. In both cases the S. boydii and E. coli O-antigen gene clusters have the same genes and organization. The clusters of both S. boydii 6 and S. boydii 9 O antigens have atypical features, with a functional insertion sequence and a wzx gene located in the orientation opposite to that of all other genes in S. boydii serotype 9 and an rmlC gene located away from other rml genes in S. boydii serotype 6. Sequences of O-antigen gene clusters from another three Shigella clones have been published, and two of them also have abnormal structures, with either the entire cluster or one gene being located on a plasmid in Shigella sonnei or Shigella dysenteriae, respectively. It appears that a high proportion of clusters coding for O antigens specific to Shigella clones have atypical features, perhaps indicating recent formation of these gene clusters.

Determination of (187)Os in molybdenite by ICP-MS with neutron-induced (186)Os and (188)Os spikes

The article describes a method for the determination of (187)Os in molybdenite by isotope dilution inductively coupled plasma-mass spectrometry (ID-ICP-MS) with neutron-induced (186)Os and (188)Os spike. The spike used in the present work was prepared in line with the principle by which artificial nuclides are produced in a nuclear reaction. The concentration and isotopic composition of osmium in the prepared spike were evaluated accurately with the isotope dilution method, using negative thermal ion mass spectrometry (N-TIMS). The advantage of this method is that using (186)Os and (188)Os double spikes can effectively compensate for the mass discrimination effects of ICP-MS. Thus, the common correction practice for mass bias in the isotope dilution method with a single spike is unnecessary. In addition, the method enables one to reduce the determined error arising from instrumental instability. The precision for the (187)Os/((186)Os+(188)Os) ratio was approximately 2% (2sigma, RSD), but in the case of (187)Os/(186)Os, (187)Os/(188)Os and (186)Os/(188)Os, precision ranged from 2.0 to 8% (2sigma, RSD). The results for (187)Os concentration in a molybdenite sample determined with this method showed good agreement with reference values.

Mechanisms of arsenic-induced cross-tolerance to nickel cytotoxicity, genotoxicity, and apoptosis in rat liver epithelial cells

The purpose of the present study was to investigate the mechanism of cross-tolerance to nickel in arsenic-transformed cells. Chronic arsenite-exposed (CAsE) cells (TRL 1215 cells, which had been continuously exposed to 0.5 microM arsenite for 20 or more weeks) and control TRL 1215 cells were both exposed to nickel for 24 h, and cell viability was determined by metabolic integrity. The LC(50) for nickel was 608 +/- 32 microM in CAsE cells as compared to 232 +/- 16 microM in control cells, a 2.6-fold increase. CAsE and control cells were treated with 200 microM nickel for 4 h and cellular-free radical production was measured using ESR spectrometry. Hydroxyl radical generation was decreased in CAsE cells. Thiobarbituric acid reactive substances, indicative of lipid peroxidation, and 8-oxo-2'-deoxyguanosine, indicative of oxidative DNA damage, were reduced in CAsE cells. Flow cytometric analysis using Annexin/FITC revealed that nickel-induced apoptosis was reduced in CAsE cells. CAsE cells showed generalized resistance to oxidant-induced toxicity as evidenced by a marked reduction in sensitivity to hydrogen peroxide. Interestingly, intracellular reduced glutathione (GSH) levels were significantly increased in CAsE cells, and when GSH was depleted, CAsE cells lost their nickel resistance. The mechanism of arsenic-induced cross-tolerance to cytotoxicity, genotoxicity, and apoptosis induced by nickel appears related to a generalized resistance to oxidant-induced injury, probably based, at least in part, in increased cellular GSH levels.

[Effect of the decoction of tribulus terrestris on mice gluconeogenesis]

The decoction of Tribulus terresteis could significantly inhibit the gluconeogenesis and influence glycometabolism on normal mice. The decoction could also reduce the level of triglyceride and the content of cholesterol in the plasma.

Blockade of receptor for advanced glycation end-products restores effective wound healing in diabetic mice

Receptor for advanced glycation end-products (RAGE), and two of its ligands, AGE and EN-RAGEs (members of the S100/calgranulin family of pro-inflammatory cytokines), display enhanced expression in slowly resolving full-thickness excisional wounds developed in genetically diabetic db+/db+ mice. We tested the concept that blockade of RAGE, using soluble(s) RAGE, the extracellular ligand-binding domain of the receptor, would enhance wound closure in these animals. Administration of sRAGE accelerated the development of appropriately limited inflammatory cell infiltration and activation in wound foci. In parallel with accelerated wound closure at later times, blockade of RAGE suppressed levels of cytokines; tumor necrosis factor-alpha; interleukin-6; and matrix metalloproteinases-2, -3, and -9. In addition, generation of thick, well-vascularized granulation tissue was enhanced, in parallel with increased levels of platelet-derived growth factor-B and vascular endothelial growth factor. These findings identify a central role for RAGE in disordered wound healing associated with diabetes, and suggest that blockade of this receptor might represent a targeted strategy to restore effective wound repair in this disorder.

Anomalous mole-fraction effects in recombinant and native cyclic nucleotide-gated channels in rat olfactory receptor neurons

Anomalous mole-fraction effects (AMFE) were studied, using the inside-out configuration of the patchclamp technique, in both recombinant wild-type alpha-homomeric rat olfactory adenosine 3',5'-cyclic monophosphate (cAMP)-gated channels (rOCNC1) expressed in human embryonic kidney cells (HEK 293) and native cyclic nucleotide-gated (CNG) channels in acutely isolated rat olfactory receptor neurons. Single-channel and macroscopic currents were activated by 200 microM and 500 microM cAMP, respectively. Macroscopic currents, measured with mixtures of Na(+)-NH(4)(+) or Cs(+)-Li(+) in the cytoplasmic bathing solution, displayed AMFE in the rOCNC1 channels at both positive and negative membrane potentials. The rOCNC1 single-channel conductance showed a distinct minimum (or maximum) in an 80% Na(+)-20% NH(4)(+) mixture (or a 60% Cs(+)-40% Li(+) mixture), but only at positive membrane potentials. Macroscopic measurements in native olfactory CNG channels with mixtures of Na(+)-NH(4)(+) indicated similar AMFE. These results suggest that both native CNG channels and recombinant alpha-homomeric channels allow several ions to be present simultaneously within the channel pore. They also further validate the dominant role of the alpha-subunit in permeation through these channels, provide the first evidence to suggest that rOCNC1 channels have multi-ion properties and further justify the use of the rOCNC1 channel as an effective model for structure-function studies of ion permeation and selectivity in olfactory CNG channels.

Cytochrome P450 CYP2J9, a new mouse arachidonic acid omega-1 hydroxylase predominantly expressed in brain

A cDNA encoding a new cytochrome P450 was isolated from a mouse brain library. Sequence analysis reveals that this 1,958-base pair cDNA encodes a 57-58-kDa 502-amino acid polypeptide that is 70-91% identical to CYP2J subfamily P450s and is designated CYP2J9. Recombinant CYP2J9 was co-expressed with NADPH-cytochrome P450 oxidoreductase (CYPOR) in Sf9 cells using a baculovirus system. Microsomes of CYP2J9/CYPOR-transfected cells metabolize arachidonic acid to 19-hydroxyeicosatetraenoic acid (HETE) thus CYP2J9 is enzymologically distinct from other P450s. Northern analysis reveals that CYP2J9 transcripts are present at high levels in mouse brain. Mouse brain microsomes biosynthesize 19-HETE. RNA polymerase chain reaction analysis demonstrates that CYP2J9 mRNAs are widely distributed in brain and most abundant in the cerebellum. Immunoblotting using an antibody raised against human CYP2J2 that cross-reacts with CYP2J9 detects a 56-kDa protein band that is expressed in cerebellum and other brain segments and is regulated during postnatal development. In situ hybridization of mouse brain sections with a CYP2J9-specific riboprobe and immunohistochemical staining with the anti-human CYP2J2 IgG reveals abundant CYP2J9 mRNA and protein in cerebellar Purkinje cells. Importantly, 19-HETE inhibits the activity of recombinant P/Q-type Ca(2+) channels that are known to be expressed preferentially in cerebellar Purkinje cells and are involved in triggering neurotransmitter release. Based on these data, we conclude that CYP2J9 is a developmentally regulated P450 that is abundant in brain, localized to cerebellar Purkinje cells, and active in the biosynthesis of 19-HETE, an eicosanoid that inhibits activity of P/Q-type Ca(2+) channels. We postulate that CYP2J9 arachidonic acid products play important functional roles in the brain.

Receptor for advanced glycation end products mediates inflammation and enhanced expression of tissue factor in vasculature of diabetic apolipoprotein E-null mice

Advanced glycation end products (AGEs) and their cell surface receptor, RAGE, have been implicated in the pathogenesis of diabetic complications. Here, we studied the role of RAGE and expression of its proinflammatory ligands, EN-RAGEs (S100/calgranulins), in inflammatory events mediating cellular activation in diabetic tissue. Apolipoprotein E-null mice were rendered diabetic with streptozotocin at 6 weeks of age. Compared with nondiabetic aortas and kidneys, diabetic aortas and kidneys displayed increased expression of RAGE, EN-RAGEs, and 2 key markers of vascular inflammation, vascular cell adhesion molecule (VCAM)-1 and tissue factor. Administration of soluble RAGE, the extracellular domain of the receptor, or vehicle to diabetic mice for 6 weeks suppressed levels of VCAM-1 and tissue factor in the aorta, in parallel with decreased expression of RAGE and EN-RAGEs. Diabetic kidney demonstrated increased numbers of EN-RAGE-expressing inflammatory cells infiltrating the glomerulus and enhanced mRNA for transforming growth factor-beta, fibronectin, and alpha(1) (IV) collagen. In mice treated with soluble RAGE, the numbers of infiltrating inflammatory cells and mRNA levels for these glomerular cytokines and components of extracellular matrix were decreased. These data suggest that activation of RAGE primes cells targeted for perturbation in diabetic tissues by the induction of proinflammatory mediators.

Stress-related gene expression in mice treated with inorganic arsenicals

Arsenic (As) is an environmental chemical of high concern for human health. Acute toxicity of arsenic is dependent on its chemical forms and proximity to high local arsenic concentrations is one of the mechanisms for cell death. This study was designed to define acute arsenic-induced stress-related gene expression in vivo. Mice were injected sc with either sodium arsenite [As(III), 100 micromol/kg], sodium arsenate [As(V), 300 micromol/kg], or saline. To examine stress-related gene expression, livers were removed 3 h after arsenic injection for RNA and protein extraction. The Atlas Mouse Stress/Toxicology array revealed that the expression of genes related to stress, DNA damage, and metabolism was altered by acute arsenic treatments. Expression of heme oxygenase 1 (HO-1), a hallmark for arsenic-induced stress, was increased 10-fold, along with increases in heat shock protein-60 (HSP60), DNA damage inducible protein GADD45, and the DNA excision repair protein ERCC1. Downregulation of certain cytochrome P450 enzymes occurred with arsenic treatment. Multiprobe RNase protection assay revealed the activation of the c-Jun/AP-1 transcription complex after arsenic treatments. Western blot analysis further confirmed the enhanced production of arsenic-induced stress proteins such as HO-1, HSP70, HSP90, metallothionein, the metal-responsive transcription factor MTF-1, nuclear factor kappa B and c-Jun/AP-1. Increases in caspase-1 and cytokines such as tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-2 were also evident. In summary, this study profiled the gene expression pattern in mice treated with inorganic arsenicals, which adds to our understanding of acute arsenic poisoning and toxicity.

[The effect of alcohol on c-fos gene expression in rat embryo neuroglial]

OBJECTIVE

This paper is aimed to explore the mechanisms of brain development abnormality induced by alcohol.

METHODS

Astrocytes and oligodendrocytes of 19-day rat embryo were exploited and cultured in vitro, and alcohol and its metabolite product (acetaldehyde) were added to DMEMF(12) medium. After different exposure times, c-fos expression of astrocytes and oligodendrocytes was measured by the immunocytochemistry technique.

RESULTS

Changes in c-fos gene expression induced by alcohol and acetaldehyde was time and dose dependent. After 1 hr exposure, alcohol and acetaldehyde affected c-fos gene expression in two kinds of neuralglia. C-fos positive expression reached peak value after 2 hr, but recovered after 72 hr and showed special time phase expression.

CONCLUSIONS

Alcohol and acetaldehyde cause abnormal increase of c-fos gene expression in astrocytes and oligodendrocytes. This abnormal expression may play an important role in abnormal brain development induced by alcohol.

[Apoptosis of retinal capillary cells in diabetic rats and expression of apoptosis-related genes]

OBJECTIVE

To determine the apoptosis of retinal capillary cells in early diabetic rats and observe the expression of apoptosis-related genes (bcl-2, Bax) in retinas of early diabetic rats.

METHODS

40 healthy adult Wistar rats were chosen and randomly divided into four groups: normal control (CON), diabetes mellitus one month (DM1), three months (DM3) and six months (DM6). Diabetic mellitus in rats was induced by streptozotocin (STZ) intraperitoneally. Retinal preparations of blood vessels and paraffin sections were stained by TdT-mediated dUTP nick end labeling (TUNEL) and immunohistochemical (ABC) method respectively and analyzed by computer-picture analytic system on the results of ABC method.

RESULTS

Positive pericyte nuclei labeled by TUNEL were emerged in DM3 and DM6, but positive endothelial cell nuclei only in DM6. No positive reaction was seen in CON and DM1. Chromatin of TUNEL positive nuclei was distributed unequally, showing apoptotic characteristics of ring-like and crescent nuclei. In ABC staining method, two genes' (bcl-2, Bax) proteins were expressed in retinal vessels. Along with the progression of diabetes, the intensity of positive reaction was increased in degrees. Moreover, pigment epithelial cells in DM3 showed Bcl-2 positive reaction that again extended further to inner rod segments and ganglion cells in DM6, while in DM6, Bax was expressed in ganglion cells.

CONCLUSIONS

The nature of pericyte dropout in early diabetic rats is apoptosis that also exists in endothelial cells; the expression of Bax and bcl-2 in retinas of early diabetic rats is enhancing.

Electro-Viscous Effects on Liquid Flow in Microchannels

The presence of the electrical double layer near a solid-liquid interface results in the electro-viscous effect on pressure-driven liquid flow through microchannels. The objective of this paper is to examine the magnitude of the additional flow resistance caused by the electrokinetic effect in microchannels. Deionized ultrafiltered water, 10(-4) and 10(-2) M aqueous KCl solutions, 10(-4) M AlCl(3) solution, and 10(-4) M LiCl solution were used as the testing liquids. Carefully designed flow measurements were conducted in three silicon microchannels with a height of 14.1, 28.2, and 40.5 µm, respectively. The measured dP/dx for the pure water, the 10(-4) M KCl solution, and the 10(-4) M LiCl solution was found to be significantly higher than the prediction of the conventional laminar flow theory at the same Reynolds number. Such a high flow resistance and the resulting high apparent viscosity strongly depend on the channel's height, the ionic valence, and the concentration of the liquids. The zeta potentials for the liquid-solid systems were calculated by using the measured streaming potential data. The experimentally determined dP/dx approximately Re relationships were compared with the predictions of a theoretical electro-viscous flow model, and a good agreement was found for pure water, 10(-4) M KCl solution, and 10(-4) MAlCl(3) solution systems. The present electrokinetic flow model cannot interpret the flow characteristics of the LiCl solution. Copyright 2001 Academic Press.

Ion permeation and selectivity of wild-type recombinant rat CNG (rOCNC1) channels expressed in HEK293 cells

The permeation properties of adenosine 3', 5'-cyclic monophosphate (cAMP)-activated recombinant rat olfactory cyclic nucleotide-gated channels (rOCNC1) in human embryonic kidney (HEK 293) cells were investigated using inside-out excised membrane patches. The relative permeability of these rOCNC1 channels to monovalent alkali cations and organic cations was determined from measurements of the changes in reversal potential upon replacing sodium in the bathing solution with different test cations. The permeability ratio of Cl(-) relative to Na(+) (P(Cl)/P(Na)) was about 0.14, confirming that these channels are mainly permeable to cations. The sequence of relative permeabilities of monovalent alkali metal ions in these channels was P(Na) > or = P(K) > P(Li) > P(Cs) > or = P(Rb), which closely corresponds to a high-strength field sequence as previously determined for native rat olfactory receptor neurons (ORNs). The permeability sequence for organic cations relative to sodium was P(NH3OH) > P(NH4) > P(Na) > P(Tris) > P(Choline) > P(TEA), again in good agreement with previous permeability ratios obtained in native rat ORNs. Single-channel conductance sequences agreed surprisingly well with permeability sequences. These conductance measurements also indicated that, even in asymmetric bi-ionic cation solutions, the conductance was somewhat independent of current direction and dependent on the composition of both solutions. These results indicate that the permeability properties of rOCNC1 channels are similar to those of native rat CNG channels, and provide a suitable reference point for exploring the molecular basis of ion selectivity in recombinant rOCNC1 channels using site-directed mutagenesis.

Analysis of the cytotoxic properties of linoleic acid metabolites produced by renal and hepatic P450s

Cytochrome P450 epoxidation of linoleic acid produces biologically active metabolites which have been associated with many pathological conditions that often lead to acute renal failure. In the present study, we evaluated the ability of specific cytochrome P450s to produce linoleic acid monoepoxides. We then tested the cytotoxic properties of linoleic acid, linoleic acid monoepoxides, and corresponding diols in a rabbit renal proximal tubule model. CYP1A2, CYP2E1, CYP2J2, CYP2J3, CYP2J5, and CYP2J9 metabolized linoleic acid at rates comparable to arachidonic acid and produced linoleic acid monoepoxides as major products. Cytotoxicity studies showed that linoleic acid, linoleic acid monoepoxides, and corresponding diols are toxic at pathologically relevant concentrations (100-500 microM). Concentration-dependent studies showed that linoleic acid and linoleic acid monoepoxides are the most toxic and induce mitochondrial dysfunction prior to cell death. Cytoprotectants known to block cell death associated with mitochondrial dysfunction and oxidative stress did not prevent cell death induced by linoleic acid and linoleic acid monoepoxides. This study shows that P450s in the CYP1 and CYP2 gene families metabolize linoleic acid to linoleic acid monoepoxides and that the monoepoxides, as well as linoleic acid, disrupt mitochondrial function without causing oxidative stress.

[Studies on the mechanisms of developmental toxicity of alcohol]

OBJECTIVE

To study the mechanisms of developmental toxicity in animals induced by ethyl alcohol.

METHOD

Rat embryos of 9.5 days of gestation were exposed to different doses of ethyl alcohol in vitro. Postimplantation whole embryo culture and fluorescence polarization technique were used to investigate the effects of alcohol on embryo development and visceral yolk sac (VYS) membrane lipid fluidity.

RESULT

400 mg alcoho/L caused no significant differences to embryo development, organ morphological scores, polarization (Pr value) and lipid fluidity unit (LFU), as compared with the non-alcohol treated controls. 1,000 mg alcohol/L led to the decrease of scores of brain, VYS circle, neurotube, head length and heart, as well as DNA and Pr value; whereas LFU values were increased significantly. Above 2,000 mg alcohol/L, all indexes were decreased except LFU of VYS cell membrane. Alcohol significantly elevated lipid fluidity of VYS cell membrane.

CONCLUSIONS

Alcohol causes development toxicity and teratogenisis in rats. Brain and VYS are the targets of alcohol effect. Its development toxicity is related with lipid fluidity and the VYS membrane damage.

Genome analysis of collagen disease in MRL/lpr mice: polygenic inheritance resulting in the complex pathological manifestations

MRL/MpJ-lpr/lpr (MRL/lpr) mice develop collagen disease involving vasculitis, glomerulonephritis, arthritis and sialoadenitis, each of which has been studied as a model for polyarteritis, lupus nephritis, rheumatoid arthritis and Sjögren's syndrome, respectively. In the previous studies, we observed genetic segregation of these complex pathological manifestations throughout the genome recombination with a C57Bl/6-lpr/lpr or a C3H/HeJ-lpr/lpr (C3H/lpr) strain of mice which rarely develops such lesions, indicating that development of collagen disease is dependent on an MRL host genetic background. To clarify the mode of inheritance and the gene loci affecting four types of the lesions in MRL/lpr mice; vasculitis, glomerulonephritis, arthritis and sialoadenitis, a genetic dissection of the lesions was carried out by using MRL/lpr, C3H/lpr, (MRL/lprxC3H/lpr) F1 intercross, and MRL/lprx(MRL/lprxC3H/lpr) F1 backcross mice. Definition of each lesion was performed by histopathology under light microscopy, and genomic DNA of the backcross mice were subjected to association studies by chi-square analysis for determining which polymorphic microsatellite locus occurs at higher frequency among affected compared to unaffected individuals for each lesion. We observed that gene loci recessively associated with each lesion were mapped on different chromosomal positions. We conclude that each of four types of the lesions in MRL/lpr mice is under the control of different set of genes, suggesting the complex pathological manifestations of collagen disease result from polygenic inheritance.

p53 accumulation due to down-regulation of ubiquitin: relevance for neuronal apoptosis

The p53 tumor suppressor protein is a major regulator of cell growth arrest and apoptosis in response to DNA damage. Both p53 function and stability are tightly controlled by Mdm2, which binds to the p53 N-terminus and targets p53 for ubiquitin-mediated proteolysis. Previous studies suggest that adrenalectomy-induced neuronal apoptosis is p53-dependent. Here we demonstrate both nuclear accumulation and functional activation of p53 protein in apoptotic hippocampal neurons from adrenalectomized rats. Increased p53 expression occurred despite the accumulation of its negative regulator, Mdm2, and the formation of p53-Mdm2 complexes. The persistence of p53 expression was explained by a striking decrease in free ubiquitin in p53-positive neurons. The addition of exogenous ubiquitin to p53-Mdm2 complexes from apoptotic neurons restored p53 degradation. These findings demonstrate a novel mechanism of p53 stabilization mediated by decreased ubiquitin levels. Regulation of free ubiquitin may therefore be an effective way to modulate p53-dependent apoptosis in certain cell types.

An absorbable pinned-ring device for microvascular anastomosis of vein grafts: experimental studies

In the rabbit, posterior facial vein segments were grafted to the femoral arteries using either conventional suture technique or a mechanical absorbable pinned-ring device. The purpose of this study was to compare patency rates and anastomotic times for the two different methods. The anastomoses were evaluated macroscopically and using light and scanning electron microscopy. The grafts anastomosed with the absorbable rings exhibited 100% patency, while only 83% of the sutured grafts were patent. The mean anastomotic time using the mechanical pinned-ring device was 18.1 min (range 9.8-30 min). The conventionally sutured anastomoses were completed in a mean time of 60 min (range 50-75 min). The experiment has confirmed that the absorbable pinned-ring device provides a safe and fast way to perform microvascular anastomosis.

Blockade of RAGE-amphoterin signalling suppresses tumour growth and metastases

The receptor for advanced glycation end products (RAGE), a multi-ligand member of the immunoglobulin superfamily of cell surface molecules, interacts with distinct molecules implicated in homeostasis, development and inflammation, and certain diseases such as diabetes and Alzheimer's disease. Engagement of RAGE by a ligand triggers activation of key cell signalling pathways, such as p21ras, MAP kinases, NF-kappaB and cdc42/rac, thereby reprogramming cellular properties. RAGE is a central cell surface receptor for amphoterin, a polypeptide linked to outgrowth of cultured cortical neurons derived from developing brain. Indeed, the co-localization of RAGE and amphoterin at the leading edge of advancing neurites indicated their potential contribution to cellular migration, and in pathologies such as tumour invasion. Here we demonstrate that blockade of RAGE-amphoterin decreased growth and metastases of both implanted tumours and tumours developing spontaneously in susceptible mice. Inhibition of the RAGE-amphoterin interaction suppressed activation of p44/p42, p38 and SAP/JNK MAP kinases; molecular effector mechanisms importantly linked to tumour proliferation, invasion and expression of matrix metalloproteinases.

Very negative potential for half-inactivation of, and effects of anions on, voltage-dependent sodium currents in acutely isolated rat olfactory receptor neurons

Previous measurements with CsF pipette solutions using whole-cell patch-clamp techniques in dissociated rat olfactory receptor neurons (ORNs) indicated that the sodium currents had very negative inactivation characteristics with the implication that the cell resting potential must also normally have a very negative value. This study supports the conclusions that such an effect was real and not dependent on either the nature of the pipette anions or the recording situation previously used. For all pipette solutions, sodium currents showed a threshold activation approximately -80 mV and half-maximal activation voltages approximately -55 with half-inactivation potential < or =-100 mV, without being significantly affected by the replacement of F(-) by other pipette anions (H(2)PO(-)(4) and acetate(-)) or the addition of nucleotides and glutathione (which did cause a very slight positive shift). F(-), followed by H(2)PO(-)(4) and to a much lesser extent by acetate(-), was the most favorable pipette anion for obtaining good seals and whole-cell sodium currents in these extremely small ORNs. These results implied that resting potentials, for viable responsive cells, should be more negative than about -90 mV, as supported by the observation that action potentials could only be evoked from holding potentials more negative than -90 mV.

99mTc-HL91 "hot spot" imaging of mice bearing human carcinoma by gamma camera and the effects of tumor necrosis on imaging

OBJECTIVE

To evaluate the hypoxia-avid agent 99mTc-HL91 (99mTc labeled 4, 9-diaza-3, 3, 10, 10-tetramethyldodecan-2, 11-dione dioxime) as the tracer of tumor "hot spot" imaging and the influence of tumor necrosis on the image.

METHODS

After injection of 99mTc-HL91, 6 nude mice bearing human breast cancer MCF-7 and 18 nude mice bearing human pancreatic adenocarcinoma were subjected to gamma camera imaging, postmortem analysis, and autoradiography and imaging of tumor sections.

RESULTS

The image of tumor was identified 1 hour after injection of 99mTc-HL91. Images demonstrated gradually increased 99mTc-HL91 uptake in the tumor 1-12 hours after injection (P < 0.05-0.001). Six hours after injection, the radioactivity ratios of tumor to thorax and tumor to head were higher than 2.1. Six hours after injection, the radioactivity ratios of tumor to brain, muscle, blood, heart, lung and kidney in pancreatic adenocarcinoma bearing nude mice were 101.0 +/- 114.7, 30.0 +/- 30.3, 19.9 +/- 21.9, 14.4 +/- 15.1, 3.71 +/- 2.41 and 0.46 +/- 0.26, respectively, and the radioactivity ratios in breast cancer MCF-7 bearing nude mice were close to these figures. The radioactivity of non-necrotic tumor was 3.77 times that of necrotic tumor. However, the radioactivity ratios of tumor to liver, intestine and stomach were lower than 1.3. Autoradiographs and images of tumor sections showed that the radioactivity was higher in the region of solid tumor than in the necrotic region.

CONCLUSION

99mTc-HL91 via gamma camera positively identifies regional tumor in nude mice bearing human cancer. 99mTc-HL91 retention is lower in necrotic tumor than in non-necrotic tumor. The low radioactivity ratio of tumor to abdominal organs limits the application of 99mTc-HL91 in detecting abdominal tumors.

A Model for Overlapped EDL Fields

A model to determine the electrical potential and ionic concentration distributions in the overlapped EDL fields between two infinitely large flat plates was developed in this paper. It was found that the treatment in the classical theory may lead to an inaccurate description due to the misuse of the Boltzmann equation. New governing equations for such an overlapped EDL field were derived. The potential distribution and ionic concentration distributions for inorganic oxide-aqueous solution systems were calculated. The results were compared with the predictions of the classical theory. Differences between our model and the classical treatment were found, especially at small separation distance. Copyright 2000 Academic Press.

Blockade of RAGE suppresses periodontitis-associated bone loss in diabetic mice

Diabetes is associated with increased prevalence, severity, and progression of periodontal disease. To test the hypothesis that activation of RAGE (Receptor for Advanced Glycation End products) contributes to the pathogenesis of diabetes-associated periodontitis, we treated diabetic mice, infected with the human periodontal pathogen Porphyromonas gingivalis, with soluble RAGE (sRAGE). sRAGE is the extracellular domain of the receptor, which binds ligand and blocks interaction with, and activation of, cell-surface RAGE. Blockade of RAGE diminished alveolar bone loss in a dose-dependent manner. Moreover, we noted decreased generation of the proinflammatory cytokines TNF-alpha and IL-6 in gingival tissue, as well as decreased levels of matrix metalloproteinases. Gingival AGEs were also reduced in mice treated with sRAGE, paralleling the observed suppression in alveolar bone loss. These findings link RAGE and exaggerated inflammatory responses to the pathogenesis of destructive periodontal disease in diabetes.

[Study on the effect of alcohol on embryonic development by using in vitro post-implantation rat whole embryo culture]

In order to explore the effects of drinking alcohol during pregnancy on embryonic development and its mechanisms, a post-implantation whole embryo culture(WEC) technique was used. The 9.5 day rat embryos were explanted in rat serum medium(immediately centrifugal serum, ICS) with alcohol(0.0.4.1.0, 2.00 and 4.00 g/L), and cultured for 48 hours. The index of embryo development and morphological scores induced by alcohol were observed. The result showed that alcohol had obviously effects on the development and growth of embryos with a dose-response relationship. Embryonic development of 0.4 g/L group was not significantly different from the control group, whereas 1.0 g/L group could interfere with the development score of mid-brain, forebrain, neurotube, and visceral yolk sac(VYS) circle obviously. All scores of the 2.00 g/L group were significantly lower than that of control group (P < 0.05). Moreover, the rate of embryo lethality and teratogenecity were obvious increased. It is concluded that alcohol has developmental toxicity and teratogenicity. The target organ affected by alcohol is brain. The effects of alcohol on the developmental differentiation of visceral yolk sac and DNA synthesis are probably related to its developmental abnormalities.

PGE(2) stimulates O(2) uptake in hepatic parenchymal cells: involvement of the cAMP-dependent protein kinase

The aim of this study was to determine which PGE(2) receptors and signal transduction pathways are responsible for the stimulation of oxygen uptake in liver. Hepatic parenchymal cells isolated from female Sprague-Dawley rats were incubated either with PGE(2), 17-phenyl-omega-trinor PGE(2) (an EP(1)-specific agonist), or 11-deoxy PGE(1) (an EP(2)/EP(4)-specific agonist), and oxygen consumption was measured. Both PGE(2) and 11-deoxy PGE(1) stimulated oxygen consumption. However, an EP(1) agonist was without effect. Although PGE(2) elevated intracellular calcium, this occurred at concentrations approximately 500-fold lower than that required to stimulate oxygen uptake. PGE(2)-stimulated increases in cAMP formation correlated well with the increase in oxygen consumption. Dibutyryl cAMP also increased oxygen consumption. Furthermore, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide, a cell-permeable inhibitor of protein kinase A (PKA), reduced the stimulation of oxygen uptake by PGE(2). Incubation of isolated parenchymal cell mitochondria with the purified catalytic subunit of PKA and ATP increased both state 3 rates of oxygen uptake and the respiratory control ratio by approximately 50%. Activation of these events was prevented by incubation with the PKA inhibitory peptide, PKI. These findings are consistent with the hypothesis that PGE(2) stimulates oxygen consumption via an EP(2) and/or EP(4) subclass of receptors through the actions of cAMP on a cAMP-dependent protein kinase.

N(epsilon)-(carboxymethyl)lysine adducts of proteins are ligands for receptor for advanced glycation end products that activate cell signaling pathways and modulate gene expression

Recent studies suggested that interruption of the interaction of advanced glycation end products (AGEs), with the signal-transducing receptor receptor for AGE (RAGE), by administration of the soluble, extracellular ligand-binding domain of RAGE, reversed vascular hyperpermeability and suppressed accelerated atherosclerosis in diabetic rodents. Since the precise molecular target of soluble RAGE in those settings was not elucidated, we tested the hypothesis that predominant specific AGEs within the tissues in disorders such as diabetes and renal failure, N(epsilon)-(carboxymethyl)lysine (CML) adducts, are ligands of RAGE. We demonstrate here that physiologically relevant CML modifications of proteins engage cellular RAGE, thereby activating key cell signaling pathways such as NF-kappaB and modulating gene expression. Thus, CML-RAGE interaction triggers processes intimately linked to accelerated vascular and inflammatory complications that typify disorders in which inflammation is an established component.

[New method for the isolation of astroglial cells and oligodendrocytes]

Based on the different properties of cellular adhesions, developmental time-courses and growth pattern of astroglial cells and oligodendrocytes, a method of isolating glial cells in vitro was developed. The observations under inverted light microscope and scan electronic microscope identified that the morphology of isolated cells were consistent with the previous description. Immunocytochemical examination showed the expressions of markers, the glial fibrillary acidic protein (GFAP) of astroglia cells and the myelin basic protein (MBP) of oligodendrocytes were consistent with the isolated cells. All parameters showed that the isolated glial cells were pure, and the new methods were easy and reliable.

Allergic lung responses are increased in prostaglandin H synthase-deficient mice

To investigate the function of prostaglandin H synthase-1 and synthase-2 (PGHS-1 and PGHS-2) in the normal lung and in allergic lung responses, we examined allergen-induced pulmonary inflammation and airway hyperresponsiveness in wild-type mice and in PGHS-1(-/-) and PGHS-2(-/-) mice. Among nonimmunized saline-exposed groups, we found no significant differences in lung function or histopathology, although PGE(2) was dramatically reduced in bronchoalveolar lavage (BAL) fluid from PGHS-1(-/-) mice, relative to wild-type or PGHS-2(-/-) mice. After ovalbumin sensitization and challenge, lung inflammatory indices (BAL cells, proteins, IgE, lung histopathology) were significantly greater in PGHS-1(-/-) mice compared with PGHS-2(-/-) mice, and both were far greater than in wild-type mice, as illustrated by the ratio of eosinophils in BAL fluid (8:5:1, respectively). Both allergic PGHS-1(-/-) and PGHS-2(-/-) mice exhibited decreased baseline respiratory system compliance, whereas only allergic PGHS-1(-/-) mice showed increased baseline resistance and responsiveness to methacholine. Ovalbumin exposure caused a modest increase in lung PGHS-2 protein and a corresponding increase in BAL fluid PGE(2) in wild-type mice. We conclude that (a) PGHS-1 is the predominant enzyme that biosynthesizes PGE(2) in the normal mouse lung; (b) PGHS-1 and PGHS-2 products limit allergic lung inflammation and IgE secretion and promote normal lung function; and (c) airway inflammation can be dissociated from the development of airway hyperresponsiveness in PGHS-2(-/-) mice.

[Effects of alcohol and metabolite acetaldehyde on the proliferation of astroglial cells of fetal brain]

To explore the mechanism of the retardation and abnormality of nerve system development induced by drinking alcohol during pregnancy, 3H-TdR incorporation was used to study the proliferation of astroglial cells of fetal brain induced by alcohol and its metabolite acetaldehyde in vitro. The results showed that alcohol and acetaldehyde obviously restrain the proliferation of astrocytes. The effect of restrain induced by acetaldehyde is stronger than that by alcohol. Nerve system development retardation and abnormality resulted from alcohol is likely to be the restrain of proliferation induced by alcohol and its metabolite acetaldehyde.

RAGE mediates a novel proinflammatory axis: a central cell surface receptor for S100/calgranulin polypeptides

S100/calgranulin polypeptides are present at sites of inflammation, likely released by inflammatory cells targeted to such loci by a range of environmental cues. We report here that receptor for AGE (RAGE) is a central cell surface receptor for EN-RAGE (extracellular newly identified RAGE-binding protein) and related members of the S100/calgranulin superfamily. Interaction of EN-RAGEs with cellular RAGE on endothelium, mononuclear phagocytes, and lymphocytes triggers cellular activation, with generation of key proinflammatory mediators. Blockade of EN-RAGE/RAGE quenches delayed-type hypersensitivity and inflammatory colitis in murine models by arresting activation of central signaling pathways and expression of inflammatory gene mediators. These data highlight a novel paradigm in inflammation and identify roles for EN-RAGEs and RAGE in chronic cellular activation and tissue injury.

Molecular cloning, enzymatic characterization, developmental expression, and cellular localization of a mouse cytochrome P450 highly expressed in kidney

A cDNA encoding a new cytochrome P450 was isolated from a mouse liver library. Sequence analysis reveals that this 1,886-base pair cDNA encodes a 501-amino acid polypeptide that is 69-74% identical to CYP2J subfamily P450s and is designated CYP2J5. Recombinant CYP2J5 was co-expressed with NADPH-cytochrome P450 oxidoreductase in Sf9 cells using a baculovirus system. Microsomal fractions of CYP2J5/NADPH-cytochrome P450 oxidoreductase-transfected cells metabolize arachidonic acid to 14,15-, 11,12-, and 8, 9-epoxyeicosatrienoic acids and 11- and 15-hydroxyeicosatetraenoic acids (catalytic turnover, 4.5 nmol of product/nmol of cytochrome P450/min at 37 degrees C); thus CYP2J5 is enzymologically distinct. Northern analysis reveals that CYP2J5 transcripts are most abundant in mouse kidney and present at lower levels in liver. Immunoblotting using a polyclonal antibody against a CYP2J5-specific peptide detects a protein with the same electrophoretic mobility as recombinant CYP2J5 most abundantly in mouse kidney microsomes. CYP2J5 is regulated during development in a tissue-specific fashion. In the kidney, CYP2J5 is present before birth and reaches maximal levels at 2-4 weeks of age. In the liver, CYP2J5 is absent prenatally and during the early postnatal period, first appears at 1 week, and then remains relatively constant. Immunohistochemical staining of kidney sections with anti-human CYP2J2 IgG reveals that CYP2J protein(s) are present primarily in the proximal tubules and collecting ducts, sites where the epoxyeicosatrienoic acids are known to modulate fluid/electrolyte transport and mediate hormonal action. In situ hybridization confirms abundant CYP2J5 mRNA within tubules of the renal cortex and outer medulla. Epoxyeicosatrienoic acids are endogenous constituents of mouse kidney thus providing direct evidence for the in vivo metabolism of arachidonic acid by the mouse renal epoxygenase(s). Based on these data, we conclude that CYP2J5 is an enzymologically distinct, developmentally regulated, protein that is localized to specific nephron segments and contributes to the oxidation of endogenous renal arachidonic acid pools. In light of the well documented effects of epoxyeicosatrienoic acids in modulating renal tubular transport processes, we postulate that CYP2J5 products play important functional roles in the kidney.

[Effects of alcohol on membrane lipid fluidity of astrocytes and oligodendrocytes]

To explore the mechanism of neuron development retardation and myelination abnormality caused by alcohol, the membrane lipid fluidity of astrocytes and oligodendrocytes which is related to neuron and myelin development were measured by using DPH fluorescence probe. The results showed that 5 mmol/L alcohol could lead to decrease the polarization of fluorescence (Pr) and increase the lipid fluidity unit of membrane in both cells. The alteration was in obvious dose-response relationship. The effect of alcohol on astrocytes was stronger than that of oligodendrocytes. It indicated that alcohol could change lipid fluidity of cell membrane. Alcohol probably plays major role in the dysfunction of astrocytes and oligodendrocytes.

[Distribution of genotypes of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 in Japanese twin children]

OBJECTIVE

In order to prevent alcohol related deseases, this study investigated the distribution of the genes controlling alcohol metabolism in Japan's twin.

METHODS

Restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) technique was used to measure the control gene of alcohol metabolized enzymes and the genotypes of alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2), which were distributed in Japan's twins. At the same time, according to the difference in genotypes, the sensitive individuals were screened from the study subjects.

RESULTS

The distribution of ADH2 and ALDH2 genes were consistent with the Hardy-weinberg equation. The three genotypes of ADH2 gene were ADH2(1)/ADH2(1) (1.1%), ADH2(1)/ADH2(2) (44.6%) and ADH2(2)/ADH2(2) (54.3%). And those of ALDH2 gene were ALDH2(1)/ALDH2(1) (41.3%), ALDH2(1)/ALDH2(2) (39.1%) and ALDH2(2)/ALDH2(2) (19.6%). The frequency of ADH2 and ALDH2 genes was 0.255, 0.745 and 0.609, 0.391 respectively.

CONCLUSION

Not only the distribution of genotypes of ADH2 and ALDH2 is known, but also the sensitive individuals are found, which can help prevent alcohol related disease.

P450 subfamily CYP2J and their role in the bioactivation of arachidonic acid in extrahepatic tissues

Historically, there has been intense interest in P450 metabolic oxidation, peroxidation, and reduction of xenobiotics. More recently, there has been a growing appreciation for the role of P450s in the oxidation of lipophilic endobiotics, such as bile acids, fat-soluble vitamins, and eicosanoids. This review details the emerging CYP2J subfamily of P450s and their role as catalysts of arachidonic acid metabolism.

Sequencing of Escherichia coli O111 O-antigen gene cluster and identification of O111-specific genes

Shiga toxin (Stx)-producing Escherichia coli strains of serogroup O111 are the most frequently isolated non-O157 strains causing outbreaks of gastroenteritis with hemolytic-uremic syndrome. The O111 O-antigen gene cluster had been cloned and about half of it has been sequenced; we have now sequenced the remainder of the gene cluster, which is 12.5 kb in length and which comprises 11 genes. On the basis of sequence similarity, we have identified all the O-antigen genes expected, including five sugar biosynthetic pathway genes, three transferase genes, the O-unit flippase gene, and the O-antigen polymerase gene. By PCR testing with E. coli strains representing all 166 O-antigen forms, some randomly selected gram-negative bacteria, and Salmonella enterica serovar Adelaide, we showed that four O-antigen genes are highly specific to O111. This work provides the basis for a sensitive test for the rapid detection of E. coli O111. This is important both for decisions related to patient care, because early treatment may reduce the risk of life-threatening complications, and for the detection of sources of contamination.

Nutritional status modulates rat liver cytochrome P450 arachidonic acid metabolism

Alterations in nutritional status affect hepatic cytochrome P450 levels. Since cytochromes P450 participate in the metabolism of arachidonic acid, we hypothesized that changes in liver P450 arachidonic acid metabolism occur during fasting and refeeding. Male Fisher 344 rats were either fed, fasted 48 hr (F48), fasted 48 hr and then refed 6 hr (F48/R6), or fasted 48 hr and then refed 24 hr (F48/R24). F48 rats had reduced body weight, increased plasma beta-hydroxybutyrate, and reduced plasma insulin compared with the other groups. Although there was no significant change in total liver P450 content, there was a significant 20%, 48%, and 24% reduction in total hepatic microsomal arachidonic acid metabolism in F48, F48/R6, and F48/R24 rats, respectively, compared with fed rats. Epoxygenase activity decreased by 28%, 51%, and 26% in F48, F48/R6, and F48/R24 rats, respectively. In contrast, omega-1 hydroxylase activity increased by 126% in F48 rats compared with fed rats. Immunoblotting revealed that levels of CYP2C11 protein were markedly reduced, whereas levels of CYP2E1 protein were markedly increased in the F48 and F48/R6 groups. In contrast, levels of CYP1A1, CYP1A2, CYP2B1, CYP2J3, CYP4A1, and CYP4A3 were unchanged with fasting/refeeding. Northern blots revealed that levels of CYP2C11 mRNAs were decreased, whereas CYP2E1 mRNAs were increased in F48 and F48/R6 rats. Recombinant CYP2C11 metabolized arachidonic acid primarily to epoxides with preference for the 14(S),15(R)-, 11(R), 12(S)-, and 8(S),9(R)- epoxyeicosatrienoic acid enantiomers. We conclude that (1) nutritional status affects hepatic microsomal arachidonic acid metabolism, (2) reduced epoxygenase activity in F48 and F48/R6 rats is accompanied by decreased levels of CYP2C11, (3) increased omega-1 hydroxylase activity is accompanied by augmented levels of CYP2E1, and (4) the effects of fasting on CYP2C11 and CYP2E1 expression occur at the pretranslational level.

Stimulation of oxygen uptake by prostaglandin E2 is oxygen dependent in perfused rat liver

The aim of this study was to determine if the effect of prostaglandin E2 (PGE2) on hepatic oxygen uptake was affected by oxygen tension. Livers from fed female Sprague-Dawley rats were perfused at normal or high flow rates (4 or 8 ml . g-1 . min-1) to vary local oxygen tension within the liver lobule. During perfusion at normal flow rates, PGE2 (5 microM) infusion increased oxygen uptake by about 50 micromol . g-1 . h-1; however, when livers were perfused at high flow rates, the increase was nearly twice as large. Simultaneously, glucose output was increased rapidly by about 50%, whereas glycolysis was decreased about 60%. When flow rate was held constant, increases in oxygen uptake due to PGE2 were proportional to oxygen delivery. Infusion of PGE2 into livers perfused at normal flow rates increased state 3 rates of oxygen uptake of subsequently isolated mitochondria by about 25%; however, rates were increased 50-75% in mitochondria isolated from livers perfused at high flow rates. Thus it is concluded that PGE2 stimulates oxygen uptake via mechanisms regulated by oxygen tension in perfused rat liver. High flow rates also increased basal rates of oxygen uptake: this increase was prevented by inactivation of Kupffer cells with GdCl3. In addition, conditioned medium from Kupffer cells incubated at high oxygen tension (75% oxygen) stimulated oxygen uptake of isolated parenchymal cells by >30% and elevated PGE2 production about twofold compared with Kupffer cells exposed to normal air-saturated buffer (21% oxygen). These effects were blocked completely by both indomethacin and nisoldipine. These data support the hypothesis that oxygen stimulates Kupffer cells to release mediators such as PGE2 which elevate oxygen consumption in parenchymal cells, possibly by mechanisms involving cyclooxygenase and calcium channels.

A multifaceted study of human papillomavirus and prostate carcinoma

BACKGROUND

The presence of human papillomavirus (HPV) in the prostate and its role in prostate carcinoma are in dispute. To address these issues, two laboratories with extensive HPV experience were selected to test specimens from two populations at different risk for prostate carcinoma, using three different polymerase chain reaction (PCR) assays and two serologic assays for HPV.

METHODS

The cases were comprised of 51 African-American (men at high risk for prostate carcinoma) and 15 Italian (men at intermediate risk for prostate carcinoma) men with prostate carcinoma. Controls were 108 African-American men and 40 Italian men with histologically proven benign prostate hypertrophy (BPH). Prostate tissue was obtained from each patient at surgery and immediately frozen in liquid nitrogen. The PCR primer sets included two (MY09/MY11 and GP5+/ GP6+) that amplify different regions of L1 and a third (WD66,67,154/WD72,76) targeted to E6. Sensitivity in the 2 L1 PCR assays was shown to be 1 HPV DNA genome per 100 cells. Serum antibodies to HPV-16 and HPV-11 virus-like particles (VLPs) were detected using enzyme-linked immunosorbent assays.

RESULTS

All available prostate carcinoma tissue specimens (n = 63) and BPH specimens from selected controls (n = 61) were tested by PCR. Human beta-globin DNA could be amplified from all specimens except three carcinomas, but no HPV DNA was detected in any case or control specimens by MY09/MY11 or E6 PCR. Microdissection of 27 carcinoma specimens was conducted to minimize nontumor DNA, but results remained negative by MY09/MY11 and GP5+/GP6+ PCR. In addition, serum specimens in cases (n = 63) and controls (n = 144) showed no differences in their responses against HPV-16 (P = 0.54) or HPV-11 VLPs (P = 0.64).

CONCLUSIONS

The findings suggest that HPV is not associated with prostate carcinoma, and that HPV DNA is not at all common in the prostate glands of older men.