Thromboxane inhibition and monocrotaline-induced pulmonary hypertension in rats

Monocrotaline (MCT)-induced pulmonary hypertension (PH) is a useful model for the investigation of this disorder in humans. The role of thrombocytes in the genesis of PH has already been addressed; however, the exact mechanism by which they induce PH remains to be elucidated. We investigated the effects of a thromboxane A2 (TXA2) synthase inhibitor (OKY-046) and a TXA2/prostaglandin H2 (PGH2) receptor antagonist (ONO-8809) on the development of MCT-induced PH. A single dose of MCT (60 mg/kg bodyweight; BW) was injected subcutaneously in Wistar rats 24 h after the administration of OKY-046 or ONO-8809. The TXA2 inhibitors were administered by gavage daily for 3 weeks. Urinary excretion of eicosanoids was determined by radioimmunoassay. At the end of the treatment period, the lungs, heart and kidneys were morphologically examined. The per cent medial thickness of the muscular pulmonary arteries (%MT) and the ratio of the right to the left ventricular mass including the septum (RV/LV + S) increased significantly in MCT-treated rats compared with the control rats. The %MT was attenuated by the administration of ONO-8809. Either OKY-046 or ONO-8809 attenuated the increase in RV/LV + S. In addition, both TXA2 inhibitors reduced urinary excretion of 11-dehydro-TXB2, particularly during the early phase of PH, suggesting that platelet aggregation was reduced. These findings suggest that the inhibition of TXA2 by synthase inhibition or receptor antagonism reduces or delays the development of MCT-induced PH in rats, probably by inhibiting platelet aggregation.

FK506 inhibits anti-IgM antibody-induced apoptosis and 17 kD endonuclease activity in the human B-cell line, MBC-1, established from Burkitt's lymphoma

The endonuclease which causes antibody-induced apoptotic cell death in B cells is not completely understood. We previously established a B-cell line (MBC-1) from a patient with Burkitt's lymphoma at the leukaemic stage which demonstrated the typical morphology and internucleosomal DNA fragmentation of apoptotic cell death when treated with anti-IgM antibody. FK506, an immunosuppressive agent and calcineurin inhibitor, partially rescued the anti-IgM antibody-induced cell death in these MBC-1 cells. DNA SDS-PAGE nuclease activity assay demonstrated that a 17 kD protein exhibited endonuclease activity. Active gel assay showed nuclease activity in the cellular nuclear extract not treated with anti-IgM antibody. This nuclease activity was inhibited by FK506 at concentrations of 10-200 ng/ml in the active gel assay. These results raise the possibility that the 17 kD endonuclease is one of the nuclear members of the immunophilin family, which may function as an endogenous endonuclease in MBC-1 cells.

A comparison of subgroups of inpatients with anorexia nervosa

OBJECTIVE

Classification of subgroups of people with anorexia nervosa has been in flux. It has not been clear whether anorexics who only purge should be grouped with pure restricters or with people who both binge and purge.

METHODS

We compared 27 restricting-type anorexics (RAN), 26 bulimic anorexics (BAN), and 34 restricting anorexics with purging behaviors (RAN-P). All subjects were underweight and recently admitted to a hospital. We excluded subjects who had not had a diagnosis of anorexia nervosa for at least 1 year duration.

RESULTS

The three groups of subjects had similar scores for Depression and Anxiety on the Beck Depression Inventory, the Spielberger State and Trait Anxiety Inventory, and on the EDI subscales aside from higher scores for BAN subjects on the Bulimia subscale.

DISCUSSION

These three subgroups of anorexia nervosa have similar degrees of dysphoric moods and core eating disorder symptoms when underweight and malnourished.

Effects of Temperature and Host on the Generation of Tomato Spotted Wilt Virus Defective Interfering RNAs

ABSTRACT The generation of defective interfering (DI) RNA molecules of tomato spotted wilt tospovirus (TSWV) was studied by serially passaging in-ocula from plant to plant under different controlled conditions. DI RNAs were generated at higher rates in plants at 16 degrees C than in plants incubated at higher temperatures. Another factor promoting the TSWV DI RNA generation was the use of high virus concentrations in the inocula. The solanaceous species Capsicum annuum, Datura stramonium, Lycopersicon esculentum, Nicotiana benthamiana, and N. rustica supported the generation of DI RNAs, whereas the virus recovered from the inoculated composite species, Emilia sonchifolia, remained free of any DI RNA under all conditions tested. This study resulted in a strategy to maintain DI RNA-free TSWV isolates, as well as in an efficient way to produce a large population of different DI RNA species. A single DI RNA species usually became dominant in an isolate after a few rounds of serial inoculations. The possible mechanisms involved in TSWV DI RNA generation under different inoculation circumstances are discussed.

Inhibition of osteoblastic cell differentiation by conditioned medium derived from the human prostatic cancer cell line PC-3 in vitro

Human prostatic carcinoma frequently metastasizes to bone tissue and activates bone metabolism, especially bone formation, at the site of metastasis. It has been reported that an extract of prostatic carcinoma and conditioned medium (CM) of a human prostatic carcinoma cell line, PC-3, established from a bone metastastic lesion, stimulate osteoblastic cell proliferation. However, there is little information about the effect of PC-3 CM on the differentiation of osteoblastic cells. In this study, we investigated the effect of PC-3 CM on the differentiation of two types of osteoblastic cells, primary fetal rat calvaria (RC) cells containing many undifferentiated osteoprogenitor cells, and ROS 17/2.8, a well-differentiated rat osteosarcoma cell line. PC-3 CM inhibited bone nodule formation and the activity of alkaline phosphatase (ALPase), an osteoblastic marker enzyme, on days 7, 14, and 21 (RC cells) or 3, 6, and 9 (ROS 17/2.8 cells) in a dose-dependent manner (5-30% CM). However, the CM did not affect cell proliferation or cell viability. PC-3 CM was found to markedly block the gene expression of ALPase and osteocalcin (OCN) mRNAs but had no effect on the mRNA expression of osteopontin (OPN), the latter two being noncollagenous proteins related to bone matrix mineralization. These findings suggest that PC-3 CM contains a factor that inhibits osteoblastic cell differentiation and that this factor may be involved in the process of bone metastasis from prostatic carcinoma.

Immunohistochemical expression of bcl-2 protein in squamous cell carcinoma and basaloid carcinoma of the esophagus

In the present study, the expression of bcl-2 protein in esophageal squamous cell carcinoma (SCC) and basaloid carcinoma (BC) was immunohistochemically examined, and its relation to tumor progression and postoperative survival was determined in SCC. A total of 42 SCC and 4 BC tumor samples were fixed with formalin, embedded in paraffin, and stained using monoclonal bcl-2 protein antibody, clone 124. Immunoreactivity was semiquantitatively scored, and the staining results were compared with the pathologic features and survival rates. The cytoplasm of basal cells from the normal esophageal epithelium was stained. In some well- and moderately differentiated SCCs, bcl-2 protein-positive reaction was observed in the peripheral part of the tumor cord, but in poorly differentiated SCC, the cells were weakly or hardly stained. However, in BC, the cells were strongly stained. The immunoreactivity was positive in 45.2% of the SCCs and all of the BCs. There were no significant differences in pathological features or patient survival between the bcl-2 protein-positive and protein-negative SCCs. In conclusion, the expression was not related to tumor progression and had no prognostic significance in SCC. Conversely, BC had strong immunohistochemical expression, probably associated with the differentiation of carcinoma cells simulating the basal cells of the esophagus.

Hemidiaphragmatic paralysis following subclavian vein catheterization

The right subclavian artery was inadvertently punctured during attempted preoperative insertion of a right subclavian venous catheter in a 59-yr-old woman undergoing radical hysterectomy. Large supraclavicular swelling became apparent soon after the arterial puncture. The postoperative chest X-ray obtained approximately 24 h after the catheterization revealed significant elevation of the right hemidiaphragm, which was further augmented on the 2nd to 4th postoperative days; oxygenation was concurrently impaired during these days. It was clinically judged that the hemidiaphragmatic paralysis was responsible for the elevated diaphragm. Both chest roentogenogram and arterial blood gas analyses started to improve on the 5th day, finally returning to normal on the 6th day. It is unlikely that the surgical procedure caused the paralysis, because it dealt only with the lower abdomen. Rather, the attempts at the subclavian venous catheterization probably caused the phrenic nerve paralysis, because the phrenic nerve travels very close to the subclavian vessels. Both the large haematoma formation following the arterial puncture and the time course of the paralysis suggest that compression of the right phrenic nerve by the haematoma, rather than needle trauma, was responsible for the paralysis.

Techniques and application of microscopic radioautography

The techniques for light and electron microscopic radioautography developed in our laboratory are described. The outlines of the applications to various tissues and organs are also briefly summarized. First, the techniques are explained in detail. These techniques can be divided into two categories, i.e., chemical fixation followed by wet-mounting radioautography and cryo-fixation followed by dry-mounting radioautography. The former is limited in application to only insoluble compounds, while the latter is universally applicable to any kind of compounds including soluble compounds. Both procedures, the chemical fixation wet-mounting procedure and the cryo-fixation dry-mounting procedure at light and electron microscopic levels are described. Next, the applications of both the procedures to various compounds are briefly mentioned. Chemical fixation with glutaraldehyde and osmium tetroxide followed by wet-mounting radioautography demonstrates insoluble macromolecular synthesis such as nucleic acids (both DNA and RNA), proteins, glucides and lipids. On the other hand, cyrofixation followed by dry-mounting radioautography demonstrates soluble small molecular compounds such as macromolecular precursors, hormones, neurotransmitters, vitamins, inorganic compounds and drugs or toxins. These procedures are expected to be applied for various inorganic and organic compounds in living organisms to elucidate the sites of their incorporation, synthesis and discharge.

Effect of simultaneous bilateral tibial nerve stimulation on somatosensory evoked potentials (SEP) in dogs

Since somatosensory evoked potentials (SEP) by hindlimb nerve stimulation are known to ascend bilaterally in the spinal cord, it was investigated whether or not simultaneous bilateral stimulation causes facilitation or inhibition of the stimuli. In an experiment using 36 adult Beagle dogs, the difference between simultaneous bilateral stimulation and unilateral stimulation was studied as to latencies and amplitudes. No significant difference was noted. However, the detection of far-field potentials by bilateral stimulation was not effective in which case far-field potentials did not recorded by unilateral stimulation. It was therefore confirmed that simultaneous bilateral stimulation does not cause facilitation or inhibition in the relay pathways, and does not affect the latency.

Water and peptide backbone structure in the active center of bovine rhodopsin

Difference FTIR spectra in the conversion of rhodopsin or isorhodopsin to bathorhodopsin were recorded for recombinant wild-type and E113Q bovine rhodopsins. Differences in various vibrational modes between E113Q and the wild-type proteins whose Schiff bases interact with chloride and Glu113, respectively, were analyzed. Water molecules in rhodopsin that change upon formation of bathorhodopsin are detected by a change in frequency of the O-H stretching vibration from 3538 to 3525 cm(-1). This change in the wild-type protein is absent in E113Q. One or a few water molecules are therefore suggested to be located in the proximity of Glu113, the counterion of the Schiff base. Another water vibration at 3564 cm(-1), which is shifted to 3542 cm(-1) in bathorhodopsin in the wild type, persists in E113Q but with approximately 5-cm(-1) shift toward higher frequency. This is due to water molecules that may be located at a site somewhat more remote from Glu113. Structural changes of some peptide carbonyls and amides are also absent in E113Q. On the other hand, the E113Q protein shows shifts of the N-H+ stretching vibrational band, that is probably due to the protonated Schiff base, upon conversion of rhodopsin to bathorhodopsin. No corresponding changes were observed in the wild type. We propose a model in which a water molecule interacts with Glu113, the protonated Schiff base, and peptide carbonyls, and amides. These residues undergo structural changes upon formation of bathorhodopsin.

Multiplication of tomato spotted wilt virus in primary cell cultures derived from two thrips species

Primary cell cultures prepared from embryos of the thrips species Frankliniella occidentalis and Thrips tabaci were tested for their potential to support replication of tomato spotted wilt virus (TSWV). Using polyclonal antibodies against the viral nucleocapsid protein (N) and indirect immunofluorescent staining, discrete spots with strong signals were observed in the cytoplasm at 48 h post-inoculation in the cell cultures of a F. occidentalis, and a T. tabaci population which failed to transmit the virus. The infection was found in approximately 40% of the monolayer cells. Using antibodies against a nonstructural protein (NSs) of TSWV, uniform and more diffused staining was observed throughout the cytoplasm of these cells, underlying active genome replication. The NSs protein accumulated slower than the N protein in the cells of both thrips species. No multiplication of TSWV was observed in a heterologous insect cell line, i.e. from Spodoptera frugiperda, suggesting the existence of specific host factors in the thrips-derived cells.

Identification of calprotectin, a calcium binding leukocyte protein, in human dental calculus matrix

Calprotectin is a calcium binding protein produced by leukocytes, macrophages and epithelial cells, and its levels in several tissues increase during infections and in many inflamed areas, suggesting that it may be an indicator of inflammatory activity. Osteopontin is a prominent phosphorylated glycoprotein in bone matrix, having calcium binding capacity. Recently, it has been reported that calprotectin and osteopontin are present in urinary stones (pathological mineralized masses in the body), and that these proteins may be involved in their formation. Dental calculus formed by mineralization of dental plaque is an inflammatory factor which may contribute to periodontal disease. It contains many organic components involved in mineralization. We recently found osteopontin molecules in human dental calculus and suggested that the components of its matrix may be similar to those of urinary stones. In this study, we investigated the presence of calprotectin in human dental calculus by immunohistochemical and immunoblotting analyses using a specific antibody for calprotectin. After fixation and demineralization of dental calculi adhered to tooth roots, sections embedded in paraffin were immunoreacted with the antibody for calprotectin and positive immunostaining for calprotectin was observed. Dental calculus proteins were then extracted with EDTA and separated by electrophoresis on 15% polyacrylamide gels. By immunoblotting analysis, 3 or 4 bands were observed at 11, 14.5, 22-25, 28 or 36.5 kDa and these patterns corresponded to those of calprotectin subunits. When non-immune rabbit serum was used instead of calprotectin-specific antibody as a negative control, no immunoreactivity was observed. These findings indicate that calprotectin is associated not only with antibacterial action but also with calcium binding capacity during dental calculus formation.

Death attributed to the toxic interaction of triazolam, amitriptyline and other psychotropic drugs

A 71-year-old man was found dead in a car into which exhaust fumes had been introduced. His wife who was in the same car recovered consciousness following hospitalization. She claimed that they had both attempted suicide by taking a large number of sleeping pills. Autopsy revealed no significant external injuries or medical disorders that would have led to the husband's death. The concentrations of alcohol and carbon-monoxide hemoglobin in his whole blood were 0.26 mg/ml and < 10%, respectively. Therefore, poisoning by carbon monoxide from the exhaust fumes was ruled out, and further toxicological examinations were undertaken. Triazolam, pentobarbital, amitriptyline and bromazepam were all detected in the tissues of the victim; whole blood concentrations were 45.60, 386.4, 521.2 and 166.7 ng/g, respectively. Triazolam (7.350 ng/g) and pentobarbital (288.2 ng/g) were also detected in the whole blood of the wife, collected 17 h after admission to hospital. When evaluating these results in the light of existing literature, we concluded that the victim and his wife had indeed attempted suicide by taking triazolam and pentobarbital. However, only the man had died of triazolam poisoning due to its apparently lethal combination with amitriptyline and other psychotropic drugs which had been prescribed to treat his depression.

Field emission SEM, conventional TEM and HVTEM study of submandibular gland in prenatal and postnatal aging mouse

The development of acinar and ductal cells of the mouse submandibular gland was studied using field emission SEM, conventional TEM and HVTEM methods. The specimens, at 15 and 18 days of gestation and 1, 3, 7, 14, 21, 30, 90 and 180 postnatal days were fixed in 2.5% glutaraldehyde solution in 0.1 M sodium phosphate buffer (pH 7.3). At 15 and 18 days of gestation, the structure of mouse submandibular gland contains acinar and ductal cells in proliferation. The cytoplasmic organelles such as mitochondria, granular endoplasmic reticulum and Golgi apparatuses are scattered in the cytoplasm. At 18 prenatal days only several acinar cells present immature secretory granules in the apical portion. In this stage the acinar and ductal cells are enveloped by bundles of fine collagen fibrils disposed in several directions. There are also numerous capillaries located closely to the acinar cell membranes. In the aging stages of 1, 3, 7, 14, 21, and 30 postnatal days, the histo-differentiation of acinar, intercalated and ductal cell components are observed. At newborn day one the cytoplasmic organelles start to place themselves around the nucleus. Several immature secretory granules are observed at day one, however, they increase in the aging days. At postnatal day 30, the cytoplasms of acinar and ductal cells are filled with a large number of secretory granules of different sizes. The stacks of granular endoplasmic reticulum and Golgi apparatus and some vesicles and free ribosomes are noted. The intercellular membranes are attached by desmosomes and cytoplasmic interdigitations. The luminal surface shows several small projections of microvilli. An electron-dense line of basement membranes followed by fine collagen fibrils are recognized. Delicate capillaries are found in the outer surface of acinar cells. At postnatal day 90 and 180 the acinar, intercalated and striated ductal cells reveal numerous secretory granules in the apical portion. The acinar cells showed basal nuclei and the parallel arrangement of granular endoplasmic reticulum. The mitochondria are located at the base of ductal cells showing a typical pattern of cristae. In these stages the intercellular digitations of cytoplasmic protrusions and desmosomes are also noted. The cytoplasm of myoepithelial cells are seen along the cell membranes. The spongy-like structures constituting the basement membrane are followed by bundles of fine collagen fibers.

Polyoxoanion-Supported Organometallic Complexes: Carbonyls of Rhenium(I), Iridium(I), and Rhodium(I) That Are Soluble Analogs of Solid-Oxide-Supported M(CO)(n)()(+) and That Exhibit Novel M(CO)(n)()(+) Mobility

The Dawson-type P(2)W(15)Nb(3)O(62)(9)(-) polyoxoanion-supported Re(CO)(3)(+) complex, [Re(CO)(3).P(2)W(15)Nb(3)O(62)](8)(-) (1), has been synthesized and characterized in two different counter-cation compositions. The [(n-C(4)H(9))(4)N](8)(8+) complex provides a highly soluble compound which exists as a single isomer in solution. The carbonyl stretching infrared frequencies suggest that the P(2)W(15)Nb(3)O(62)(9)(-) ligand serves as a strong electron donor to the Re(CO)(3)(+) fragment. The P(2)W(15)Nb(3)O(62)(9)(-) polyoxoanion-supported Ir(CO)(2)(+) complex [Ir(CO)(2).P(2)W(15)Nb(3)O(62)](8)(-) (2) has also been synthesized and characterized as its octakis(tetrabutylammonium), [(n-C(4)H(9))(4)N](8)(8+), salt. This compound was characterized by NMR and IR, results which demonstrate that 2 also exists as a single isomer in solution. The [Ir(CO)(2).P(2)W(15)Nb(3)O(62)](8)(-) complex is stable in the absence of water, but decomposes quickly in the presence of even 1 equiv of water. Attempted preparation of the analogous P(2)W(15)Nb(3)O(62)(9)(-) -supported Rh(CO)(2)(+) complex (3), while monitoring by (31)P NMR, revealed that this compound is unstable in solution at room temperature. In addition, we have discovered that added Na(+) can induce the formation of non-C(3)(v)() symmetry isomers of supported Re(CO)(3)(+) and Ir(CO)(2)(+) and, by inference, supported Ir(1,5-COD)(+). When Na(+) is removed from these systems by addition of Kryptofix[2.2.2], the non-C(3)(v)() isomers convert back to the single, C(3)(v)() isomer with heating, thereby providing a model system for the little studied mobility of M(CO)(n)()(+) cations across a soluble-oxide surface. When [Rh(CO)(2).P(2)W(15)Nb(3)O(62)](8)(-) is irradiated in the presence of hydrogen and cyclohexene a novel polyoxoanion-stabilized Rh(0)(n)() nanocluster is formed, results that bear a strong analogy to Yates' work studying atomically-dispersed Rh(CO)(2)(+) on solid Al(2)O(3).(10e) Yates and co-workers observe that Rh(CO)(+).Al(2)O(3) loses a CO upon photolysis, and that the resultant Rh(CO)(1)(+).Al(2)O(3) is reduced under H(2) to form Rh(0), which in turn yields Rh(0)(n)() clusters on Al(2)O(3)-a process that, intriguingly, is largely reversible if CO is readded. Also briefly discussed is other relevant literature of solid-oxide-supported Re(CO)(3)(+) and M(CO)(2)(+) (M = Ir, Rh), literature that makes apparent the potential significance of these complexes as EXAFS and other spectroscopic models of solid-oxide-supported M(CO)(n)()(+).

Hexagonal structures at lens capsule zonular attachments

Two years after uneventful phacoemulsification with posterior intraocular lens implant in an 84-year-old female patient, the capsular bag and enclosed intraocular lens luxated into the vitreous cavity. A vitrectomy was done to extract the lens and capsule for electron-microscopic examination. We found very few zonular attachments to the capsule, but did note hexagonal structures of unknown significance that our study indicates may be related to the lens epithelium.

Development and DNA synthesis in the retina of chick embryo observed by light and electron microscopic radioautography

The incorporation of 3H-thymidine into DNA was examined in the chick embryo retina in early development during the period of the optic vesicle formation (day 2) before the formation of the basic layers of retina (day 7) by means of light and electron microscopic radioautography. Labeling index with 3H-thymidine reached the maximum on day 2 and declined thereafter. The patterns of localization of labelled cells and average grain counts were compared in the anterior, equatorial and posterior regions of the retina. On day 2, more labelled cells were found in the posterior region than the other two regions of the retina. Most of the labelled cells were found in the outer portion of the retinal layer throughout the retina. On day 3, most labelled cells were found in the anterior region and decreased in the posterior one. On day 4, labelled cells dominated in the anterior and equatorial regions. In these two regions, more labelled cells were present in the outer portion of the retinal layer, while in the posterior region these cells were seen in the inner portion of the retinal layer.

Structural properties and RNA-binding activities of two RNA recognition motifs of a mouse neural RNA-binding protein, mouse-Musashi-1

mouse-Musashi-1 (m-Msi-1) is an RNA-binding protein, abundantly expressed in the developing mammalian central nervous system (CNS). m-Msi-1 contains two RNA recognition motifs (RRMs). In this study, we found that the N-terminal RRM of m-Msi-1 (MMA) binds strongly to poly(G) and weakly to poly(U) in a way similar to that of the full-length m-Msi-1 protein characterized previously. The C-terminal RRM of m-Msi-1 (MMB), however, does not bind to RNA. In addition, the circular dichroism (CD) spectra of the two RRMs showed that the alpha-helical content of MMA is significantly higher than that of MMB, indicating that some differences in the secondary structure may be responsible for the distinct RNA binding properties of MMA and MMB.

Epitope selection in major histocompatibility complex class I-mediated pathway is affected by the intracellular localization of an antigen

We analyzed the mode of antigen presentation of an endogenous antigen localized in the cytoplasm or in the mitochondria. Pseudomonas aeruginosa PAO leucine-, isoleucine-, valine-binding protein (LIVAT-BP) encoded by the braC gene was used as a model antigen. Using mouse BALB/3T3 cells, we established two LIVAT-BP transfectants by transfection of a plasmid harboring the intact braC or braC gene fused with the mitochondrial transport signal derived from the yeast COXIV gene. One of the resulting transfectants, BC-15, expressed LIVAT-BP in the cytoplasm, while YZ-710 cells expressed LIVAT-BP in the mitochondria. The splenic effector cells derived from BALB/c mice primed with BC-15 cells exhibited cytotoxic T lymphocyte (CTL) activity against BC-15 cells, but not against YZ-710 cells, whereas splenic effector cells primed with YZ-710 cells exhibited CTL activity against YZ-710 cells, but not against BC-15 cells. Neither group of splenic effector cells showed CTL activity against parental BALB/3T3 cells. These CTL belonged to the CD8+ alphabeta T cell subset. Furthermore, we observed that the CTL activity against t BC-15 cells or YZ-710 cells was blocked with anti-H2-K(d) mAb, but not with anti-H2-D(d) or H2-L(d) mAb. The CTL against BC-15 or YZ-710 cells could kill parental BALB/3T3 cells in the presence of peptides produced by alkali lysis of the LIVAT-BP, suggesting that these CTL indeed recognized the peptide(s) derived from LIVAT-BP. We determined that the epitope for the CTL against BC-15 cells was QYGEGIATEV, corresponding to residues 162-171, and that the epitope recognized by the CTL against YZ-710 cells was GYKLIFRTI, corresponding to residues 123-131 of LIVAT-BP, respectively. Thus, we show here that epitope selection for MHC class I expression is affected by the intracellular localization of the antigenic protein.

Inhibition of arachidonate lipoxygenase activities by 2-(3,4-dihydroxyphenyl)ethanol, a phenolic compound from olives

The effects of olive fruit extract on arachidonic acid lipoxygenase activities were investigated using rat platelets and rat polymorphonuclear leukocytes (PMNL). Olive extract strongly inhibited both 12-lipoxygenase (12-LO) and 5-lipoxygenase (5-LO) activities. One of the compounds responsible for this inhibition was purified and identified as 2-(3,4-dihydroxyphenyl)ethanol (DPE). DPE inhibited platelet 12-LO activity (IC50, 4.2 microM) and PMNL 5-LO activity (IC50, 13 microM) but not cyclooxygenase activity in cell-free conditions. It also inhibited 12-LO activity in intact platelets (IC50, 50 microM) and reduced leukotriene B4 production in intact PMNL stimulated by A23187 (IC50, 26 microM). The inhibition by DPE of both lipoxygenase activities was stronger than that by oleuropein, caffeic acid, or 7 other related phenolic compounds, especially in intact cells. These results suggest that DPE is a potent specific inhibitor of lipoxygenase activities.

Identification of catechin oligomers from apple (Malus pumila cv. Fuji) in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and fast-atom bombardment mass spectrometry

Molecular size information for polymerized catechin larger than the decamer in unripe apple was obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and by fast-atom bombardment mass spectrometry. Matrix-assisted laser desorption/ionization time of flight mass spectrometry provided evidence for the pentadecamer using trans-3-indoleacrylic acid as the matrix in the presence of silver ion. Even in the absence of silver ion, the dodecamer and undecamer were observed in the positive- and negative-ion modes, respectively. Fast-atom bombardment mass spectrometry also afforded evidence for the undecamer in both positive- and negative-ion modes.