Volume 56, Issue 3-4

After an injury of the central nervous system it is of foremost clinical concern to prevent nerve cell degeneration and to develop strategies for the support of axonal regeneration. This requires an understanding of traumatic processes in the nervous system and their regulation by intercellular cytokine signaling. Although injury-induced temporal changes in gene expression of many cytokines have been described in this context, much less is known about their regulation. This review proposes a role of retinoic acid (RA) as transcriptional regulator in nerve regeneration. Four lines of evidence support this hypothesis: (1) In various cell culture systems retinoids were found to interact with most cytokine signals that mediate cellular interactions after nerve lesions in vivo. (2) Necessary components of the retinoid signaling pathway (aldehyde dehydrogenases, nuclear RA-receptors, cellular RA-binding proteins) are present in the adult nervous system, and glial cells produce RA in vitro. In addition, recent observations indicate that RA-synthesizing enzyme activity increases after nerve injury. (3) During development endogenous RA promotes glial and neuronal differentiation including the outgrowth of axons in the developing spinal cord, cerebellum, dorsal root ganglia and sympathetic ganglia. (4) Axonal regeneration of differentiated retinal ganglion cells and peripheral sensory neurons is enhanced by RA in vitro.

The major 3-deoxyanthocyanin isolated from the fern Blechnum novae-zelandiae was de­termined to be luteolinidin 5-O-β-ᴅ-[3-O-β-ᴅ-glucopyranosyl-2-O-acetylglucopyranoside] and was found to co-occur with quercetin 3-O-β-ᴅ-[6-O-caffeoylglucopyranoside], quercetin 3-O-β-ᴅ-[6-O-caffeoylgalactopyranoside] and kaempferol 3-O-β-ᴅ-glucuronopyranoside. These pigments were identified by using HPLC chromatography, NMR (1ᴅ , 2ᴅ) and electrospray mass spectroscopy.

, 2001 Three new sesquiterpenoids, lubiminoic acid, epilubiminoic acid and aethione, and six known sesquiterpenoids, solavetivone, 3β-hydroxysolavetivone, 13-hydroxysolavetivone, an-hydro-β-rotunol, epilubimin and lubimin, were isolated from roots of S. aethiopicum L. Their structures were elucidated by spectroscopic data.

We have found that the binding of NADP + (K d = 0.86 ±0.11 μᴍ) enhanced the FAD fluorescence of Arabidopsis thaliana NADPH :thioredoxin reductase (TR, EC 1.6.4.5) by 2 times, whereas the binding of 3-aminopyridine adenine dinucleotide phosphate (AADP + ) (K d < 0.1 μᴍ) quenched the fluorescence by 20%. Thioredoxin (TRX) also enhanced the FAD fluorescence by 35%. The K d of TR-NADP + and TR-AADP + complexes did not change in the presence of 45 μᴍ TRX. Our findings imply that the binding of NADP + and AADP + at the NADP(H)-binding site of A. thaliana TR, and/or the binding of TRX in the vicinity of the catalytic disulfide increase the content of fluorescent FR conformer (NADP(H)-binding site adjacent to flavin). The different effects of NADP + and AADP + on FAD fluorescence intensity may be explained by the superposition of two opposite factors: i) increased content of fluorescent FR conformer upon binding of NADP + or AADP + ; ii) quenching of FAD fluorescence by electron-donating 3-aminopyridinium ring of A ADP + .

The effects of jasmonic acid (JA) and abscisic aid (ABA) on secondary metabolism in barley (Hordeum vulgare L.) were investigated. Treatment with JA at 100 μᴍ for 48 h induced accumulation of four compounds in barley primary leaves. The accumulation of these com­pounds was also observed after treatment with ABA at 100 μᴍ. The induced compounds were identified as p-coumaroylputrescine, p-coumaroylagmatine, p-coumaroyl-3-hydroxyagmatine and tryptophan by spectroscopic methods. The profiles of compounds induced by application of JA and ABA were different. JA exhibited stronger inducing activity for hydroxycinnamic acid amides than ABA, while ABA was more active in tryptophan accumulation. The major hydroxycinnamic acid amides in JA-and ABA-treated leaves were p-coumaroylagmatine and p-coumaroyl-3-hydroxyagmatine, respectively. These differences suggested that JA and ABA act in distinct modes. The induction of these compounds was also observed in leaf segments treated with 1 ᴍ sorbitol and glucose. These findings suggested that JA and ABA are involved in accumulation of hydroxycinnamic acid amides and tryptophan in response to osmotic stress in barley.

The decrease of the number of ring nitrogen atoms of 2-benzylamino-4-methyl-6-trifluoro-methyl-1,3,5-triazines on herbicidal activity and inhibition of photosynthetic electron trans­ port (PET) was assayed using thylakoids from Spinacia oleracea or atrazine-resistant Chenopodium album. Three 2-benzylamino-4-methyl-6-trifluoromethyl-1,3,5-triazines, nine pyrimidines with a benzylamino-, methyl-and trifluoromethyl-group, 2-benzylamino-6-methyl-4-trifluoromethyl-pyridine and N-benzyl-3-methyl-5-trifluoromethylaniline were synthesized and assayed. 2-(4-Bromobenzylamino)-4-methyl-6-trifluoromethylpyrimidine exhibited the highest PET inhibitory activity against Spinacia oleracea thylakoids of all compounds tested. The 2-benzylaminopyrimidines and 2-methylpyrimidines having a 4-halobenzylamino group exhibited higher PET inhibition than atrazine and 2-trifluoromethylpyrimidines against Spinacia oleracea thylakoids. These PET inhibitory active compounds also exhibited a strong and similar inhibition both against atrazine-resistant Chenopodium album thylakoids as well as against thylakoids from wild-type Chenopodium. The herbicidal activity of 4-(4-bromoben-zylamino)-2-methyl-6-trifluoromethylpyrimidine was equivalent to that of known herbicides like simetryne, simazine or atrazine.

The chemical composition of the volatile metabolites of Crithmum maritimum harvested from several geographic localities along the Mediterranean coasts was studied by GC and GC-MSD. The major oil constituents were found to be dillapiole, γ-terpinene, sabinene, limo-nene and β-phellandrene. The Western populations were richer in dillapiole, whereas the Southern collections were characterized by increased amounts of thymol methyl ether and y-terpinene. The Italian chemical profiles differentiated by the significant contributions of carvacrol methyl ether and isoterpinolene. The essential oils were also investigated for their insecticidal activity and their repellency against Pheidole pallidula (Nylander) ants and found to possess significant activity.

Microbial bioconversion studies conducted on the diterpene psiadin have revealed that it was metabolized by Aspergillus niger (NRRL 2295) to give 2α-hydroxydeoxopsiadin, Cunninghamella blakesleeana (ATCC 8688a) to give 11β-hydroxypsiadin, and Cylindrocephalum aureum (ATCC 12720), Gongronella butleri (ATCC 22822), Kloeckera africana (ATCC 20111), and Kluyveromyces marxianus var. lactis (ATCC 2628) to yield 7α-hydroxypsiadin. Their structures have been established on the basis of spectral data. The structure and relative stereochemistry of 7α-hydroxypsiadin was confirmed by single-crystal X-ray analysis.

Microbial transformation studies on 2β-angeloyloxy-5β,8β-dihydroxypresilphiperfolane have revealed that it was metabolized by a number of microorganisms. Using a standard two-stage fermentation technique, Mucor ramannianus (ATCC 9628) produced three metabolites. One of them was characterized as the novel metabolite (2'R,3'R)-(+)-2β-(2',3'-epoxyangeloyloxy)-5β,8β-dihydroxypresilphiperfolane on the basis of spectral data. The absolute configuration at both oxirane carbons was confirmed by hydrolysis product of the novel metabolite which is (2R,3R)-(+)-2,3-epoxyangelic acid.

Treatment of potato tuber tissues with β-1,3-glucooligosaccharide induces accumulation of (S)-N-p-coumaroyloctopamine (p-CO). We examined the role of reactive oxygen species (ROS) and nitric oxide (NO) in the signal transduction leading to p-CO accumulation. Induction was suppressed by an NADPH -oxidase inhibitor, diphenyleneiodonium chloride, and oxygen radical scavengers. H 2 O 2 was generated in the tuber tissue within a few minutes of treatment with β-1,3-glucooligosaccharide. On the other hand, treatment with NO specific scavenger, nitric oxide synthase inhibitor, and serine protease inhibitor did not inhibit p -CO induction. Our findings suggest that ROS generated by the action o f NADPH -oxidase play an important role in this system, while NO and serine protease are unlikely to be involved in this process.

Solanum genotypes that differ in the level of polygenic resistance to the oomycete plant pathogen Phytophthora infestans were studied for their oxidative response to culture filtrate (CF) of the pathogen. Reactive oxygen species (ROS) production, peroxidase activity and lipid peroxidation have been studied in the CF-treated cell suspensions derived from leaves of the resistant S. nigrum (nonhost) and 5. tuberosum cv. Bzura as well as from the susceptible S. tuberosum cv. Tarpan and clone H-8105. In both the resistant and susceptible cells the CF induced similar processes, but these varied with respect to the kinetics and intensity. In all cells probably the membrane-bound NADPH oxidase, was responsible for the ROS production. This process was more intensive and prolonged in the susceptible cells than in the resistant ones. The CF treatment slightly affected peroxidase activity in all cells studied. Lipid peroxidation that occurred as a consequence of the ROS accumulation was pronounced mainly in the susceptible cells. We suggest that lack of stringent control of the oxidative processes and sensitivity to the pathogen toxins may be decisive for limited polygenic resistance in potato.

A lepidopteran toxin gene, cryIC (pSB607) from entom opathogenic Bacillus thuringiensis subsp. aizawai was introduced into nitrogen-fixing A zospirillum lipoferum by transformation. Regeneration of spheroplasts was achieved at 99% with 39% frequency of regeneration. Transformants were screened on NB kanamycin with ampicillin plates and 4 transformants were selected after ten generations. SDS-PAGE and Western blot analysis confirmed the presence of a 68 kDa protein in the transformants. Studies on utilization of carbon sources indicate that glucose and sucrose are the most favorable carbon sources and 2 % molasses is the cheap alternate carbon source for the better growth of parent A. lipoferum and transformants.

During our studies on the components in Japanese cedar, Cryptomeria japonica, we found that the crude methanol extract of C. japonica showed intense antifeeding activity against one snail species, Acusta despesta, which is well-known as a pest of many vegetables and crops. The active components in the extract were separated into the hexane and ethyl acetate soluble fractions. From the active ethyl acetate soluble fraction, two norlignans, sequirin-C and agatharesinol, were isolated and identified as the active compounds. Both compounds inhibited feeding behavior of A. despesta at 30 μg/cm 2 and 40 μg/cm 2 concentrations, respectively, when applied by an eggplant leaf or filter paper containing 20 μl of 5% sucrose solution.

Screening chemical compounds, we found that a xenoestrogen, bisphenol A , showed potent repellent activity against the zoospores of A phanomyces cochlioides. Based on this finding, we tested a number of androgenic and estrogenic compounds (e.g. testosterone, progesterone, estradiols, diethylstilbestrol, estrone, estriol, pregnenolone, dienestrol etc.) on the motility behavior of A. cochlioides zoospores. Interestingly, most of the estrogenic compounds exhib­ited potent repellent activity (1 μg/ml or less by the "particle method") toward the motile zoospores of A. cochlioides. We derivatized some of the estrogens and discussed the relation­ ship between the structure of active molecules and their repellent activity. Apparently, aromatization of the A ring with a free hydroxyl group at C-3 position of a steroidal structure is necessary for higher repellent activity Interestingly, methylation of diethylstilbestrol (DES) yielded completely different activity i.e. both mono-and di-methyl ethers of DES showed attractant activity. Moreover, the attracted zoospores were encysted and then germinated in the presence of di-methyl ether of DES. The potential usefulness of this repellent test is discussed for the detection of estrogenic activity of naturally occurring compounds, and the possible role of phytoestrogens in host/parasite interactions. So far, this will be the first report of repellent activity of estrogenic compounds toward trivial fungal zoospores.

The antennal responses of codling moth females, Cydia pomonella, to volatiles from apple branches with green fruits were recorded by electroantennography coupled to gas chroma­ tography. The antennae strongly responded to 4,8-dimethyl-1,3(E),7-nonatriene, linalool, β-caryophyllene, (E)-β-farnesene, germacrene D, (Z,E)-α-farnesene, (E,E)-α -farnesene and methyl salicylate. These compounds were all present in volatile collections on Porapak Q from both living and cut branches. Analysis by the solid phase microextraction technique (SPME) showed that the emission of some electrophysiologically active compounds increased after branches had been cut, especially 4,8-dim ethyl-1,3(E),7-nonatriene, linalool and (E,E)-α-farnesene. The identification of apple volatiles eliciting antennal responses is the first step towards the identification of compounds mediating host-finding and oviposition in codling moth females.

Viscidone (0.5%), vanillin, 3',4'-(methylendioxy)acetophenone, 3-ethoxy-4-methoxybenz-aldehyde, cinnamic acid, 3-methoxy-4-hydroxymethyl ester were isolated from propolis of hives from Cuncumen. This is the first report on propolis composition of an arid and a Mediterranean type climate area.

Pinocembrin, acacetin, galanguin, izalpin, kaempferide, prenyletin and diarytheptane were isolated from propolis from Central Chile.

The in vitro effects of the toxin coumarin compounds scopoletin and aflatoxin B 1 (AFB 1 ) on bovine (Bos indicus) hepatic mitochondrial respiratory complex III enzymes, succinate cytochrome c and a-ketoglutarate cytochrome c reductases, were examined. Kinetic studies on the interaction of the toxins with the enzymes were also carried out. The results showed that although the observed inhibitory and stimulatory effects of the two toxins were consistent with the changes in the kinetic parameters (K m and V max values), these parameters were not consistent with the observed effects of the toxins at certain concentrations. These observations are discussed in terms of the relative locations of the enzymes in the mito­chondria, and the previously reported inhibitory and uncoupling effects of the toxins on cow liver mitochondrial respiration.

Changes of lipoprotein secretion and composition in response to CCl 4 treatment were studied in monolayer cultures of rat primary hepatocytes. (1) CCl 4 decreased secretion of very low density lipoproteins (VLDL) by about 85%, while high density lipoprotein (HDL) secretion was less affected (about 40%). The effect was concentration-dependent. (2) CCl 4 significantly inhibited secretion of VLDL-and HDL-associated triglycerides and cholesterol esters. VLDL-and HDL-associated cholesterol was not affected, while secretion of phospholipids was increased. (3) Hepatocytes secreted the apolipoproteins B 48 , B 100 , E, C, and A-I. CCl 4 reduced secretion of apoproteins associated with VLDL by almost 20%, and by about 75% when associated with HDL. The de novo synthesis of apolipoproteins was attenuated by CCl 4 . (4) CCl 4 caused variations in the apolipoprotein composition in VLDL and HDL. CCl 4 intoxication of the liver affected the morphology and/or function of the lipoproteins, which drastically impaired their ability to act as transport vehicles for lipids from the liver to the circulation.

Elafin and secretory leukocyte protease inhibitor (SLPI) are two structurally related serine protease inhibitors present in the lung. The cellular origin of elafin in the alveolar space is unknown. It has been suggested that at least one alveolar leukocyte population express elafin. We therefore postulated that the alveolar macrophage, as the most numerous leukocyte in the alveolar space, express elafin. On the other hand, it is unclear whether human alveolar macrophages are a source of SLPI. In the present study, we showed by RT-PCR that human alveolar macrophages, but not peripheral blood monocytes, express elafin and SLPI transcripts. Elafin, but not SLPI, m RNA expression was increased time dependently in alveolar macrophages stimulated with Saccharopolyspora rectivirgula antigen (50 μg/ml), a causative agent of hypersensitivity pneumonitis, but not LPS (10 μg/ml). Intracellular or cell-associated elafin protein accumulated after 24 h of culture only in S. rectivirgula antigen-stimulated alveolar macrophages as shown by Western blot. In contrast, alveolar macrophages release 50 ± 6 pg/ml of SLPI in culture medium with no increase in function of time. Alveolar macrophages could be a source of elafin in the lung. In addition to lung structural cells, SLPI could also be derived from alveolar macrophages.

The stress response of eukaryotic cells is characterized by changes in the metabolism of responding cells, most notably by increased synthesis of a group of proteins known as heat shock (HSP) proteins. In this paper the effect of prostaglandin A 1 (PGA 1 ), arsenite and aspirin in Aedes albopictus cells was investigated. In cells treated with PGA 1 (10 μg/ml) we observed the induction of several polypeptides with molecular masses of 87, 80, 70, 57, 29 and 23 kDa. Immunoblot analysis revealed that arsenite induces a marked synthesis of HSP70, and aspirin administered during the hyperthermic treatment caused a small increase of HSP70 synthesized.

From Pseudomonas putida CFML 90-44 an isopyoverdin was isolated. Its structure could be elucidated by chemical degradation and spectroscopic data.

By a feeding experiment with a 15 N-labelled precursor it is shown that ferribactins are transformed into pyoverdins and thus are their biogenetic precursors.

The green microalga Apatococcus constipatus was in­ vestigated for its fatty acid composition using GC and MS techniques. Considerable variations were found in individual fatty acid contents according to the stage of culture development. A set of saturated fatty acid homologues was distinguished as the main component regard­ less of the culture age. The occurrence of some uncommon fatty acids in minor amounts, such as hydroxylated ones, was found to be characteristic o f the studied species. Depending on the development stage, those com ­ pounds were detected either only during initial growth phases or throughout the cultivation time.

Injection of three different organotin compounds such as tripalmitin, fentin and fenbutatin produced a significant increase in the hemolymph sugar level of intact crabs at Oziotelphusa senex senex apparently by stimulating release of the hyperglycemic hormone (HGH).