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PubMed1996

Poly(3-hydroxybutyrate) is associated with specific proteins in the cytoplasm and membranes of Escherichia coli.

Poly(3-hydroxybutyrate) (PHB) is well-known as a high molecular weight homopolymer of R-3-hydroxybutyrate which accumulates in storage granules within the cytosols of certain bacteria. Escherichia coli does not amass these granules; however, small amounts of low molecular weight PHB (<0.02% of dry weight) have been found in the plasma membranes in complexes with calcium polyphosphate; the complexes serve as voltage-activated calcium channels. Here we report that polyphosphate-complexed PHB is only a minor fraction of the polyester in E. coli. PHB comprises 0.36 to 0. 55% of the dry weight of log-phase cells, depending on culture medium, and this amount increases by 15 to 20% when the cells are made genetically competent. The PHB is widely distributed throughout the cell, wherein it is primarily associated with proteins. The identity of protein-associated PHB was established by antibody reaction, chemical assay, and 1H NMR spectroscopy. As expected, the physical and chemical properties of protein-associated PHB were found to be considerably different from those of the bulk polymer or granule PHB, e.g. protein-PHB complexes are normally insoluble in chloroform, soluble in water and alkaline hypochlorite, and are converted to crotonic acid more slowly on heating in concentrated sulfuric acid. Our studies indicate that the majority of cellular PHB (over 80%) is located in cytoplasmic proteins, especially proteins of the ribosomal fraction. Western immunoblots, probed with polyclonal anti-PHB IgG, revealed a number of PHB-polypeptides having a wide range of molecular weights in all cell fractions. These results suggest that PHB is a fundamental constituent of cells that may have physiological functions in addition to facilitating ion transmembrane transport or serving as a carbon reserve.

Bacterial Proteins↗
PubMed2002

Topical anti-inflammatory activity of Bauhinia tarapotensis leaves.

The topical anti-inflammatory properties of Bauhinia tarapotensis Benth. (Leguminosae) leaves have been studied by the inhibition of the croton oil-induced ear edema in mice. A bioassay-guided fractionation showed an interesting anti-inflammatory activity of the chloroform extract, that justifies the activity of the whole herbal drug. The main anti-inflammatory principles of B. tarapotensis leaves are triterpenic acids of ursane and oleanane series. The antiphlogistic activity of mixtures constituted of two ursane and oleanane isomers with different hydroxylation pattern, in the ratio 2:1, is comparable to that of indomethacin (ID50 ranging from 95 to 147 microg/cm2 and 93 microg/cm2, respectively).

Animals↗
PubMed2001

Cancer chemopreventive activities of S-3-1, a synthetic derivative of danshinone.

Salvia miltiorrhiza is a traditional Chinese medicine which has been well documented for its anti-cancer effects. Based on the structure of danshinone, one of the active compounds derived from Salvia miltiorrhiza, we synthesized a simplified phenolic analog, S-3-1, and tried to explore its possible actions in preventing the development of cancer. With the Ames test, S-3-1 was found to efficiently suppress the mutagenicity of benzo[alpha]pyrene. This result is consistent with the inhibitory effect of S-3-1 on the activation of benzo[alpha]pyrene by hepatic microsomal enzymes. Besides the anti-initiation effects, S-3-1 could significantly inhibit the croton oil-induced increase of mouse skin epithermal ornithine decarboxylase activity. Moreover, S-3-1 quenched both superoxide and hydroxyl free radicals whereas it inhibited lipid peroxidation in the in vitro model. These results suggest that S-3-1 might act as anti-initiation and anti-promotion agents through reversing the biochemical alterations induced by carcinogen during carcinogenesis. Therefore, we further investigated the effects of S-3-1 on carcinogenesis. In vitro, S-3-1 inhibited the benzo[alpha]pyrene-induced transformation of V79 Chinese hamster lung fibroblasts. At 10-40 mg/kg, S-3-1 was found to inhibit the development of DMBA/croton oil-induced skin papilloma in mice through decreasing the incidence of papilloma, prolonging the latent period of tumor occurrence and reducing tumor number per mouse in a dose-dependent manner. We concluded from this study that S-3-1 might be developed as a new chemopreventive drug.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1982

[Carcinogenicity test in long-term bioassay of Fermosin-yeast grown on petroleum hydrocarbons].

To test "fermosinR'-yeast grown on petroleum hydrocarbons for carcinogenic potency the product was fed chronically at a dietary level of 15% to male and female rats (Wistar). Animals of the control group received the Institute's stock diet, similar to the yeast diet but without "fermosinR'. Feeding of "fermosinR'-diet did not affect the incidence nor the latency period nor the type of tumors compared with the control rats. Studies in mice (XVII) included two separate experiments. In the first one the dorsal skin of the animals was painted by extracts from yeast twice weekly and treated with the co-carcinogenic agent croton oil once a week. In the second experiment the mice were painted by extracts from pork of animals feed with "fermosinR'. The results obtained in rats and in mice did not reveal any evidence for carcinogenic potency of "fermosinR'-yeast.

Administration, Oral↗
PubMed1966

The liver as the site of C-reactive protein formation.

The site of formation of C-reactive protein (CxRP, CRP) has been studied with tissues from rabbits, monkeys, and human beings. Rabbits and monkeys were stimulated to produce the acute phase protein by injection of turpentine, croton oil, endotoxin, paratyphoid-typhoid vaccine, or pneumococci. C(14)-amino acid incorporation in vitro was demonstrated by means of autoradiography of immunoelectrophoretic patterns made with culture fluids. It was found that among many different tissues tested liver was the only tissue which incorporated C(14)-lysine and isoleucine into CxRP or CRP. Only livers taken 16 to 24 hr after various stimuli were active; livers from normal animals or from animals killed 3 to 9 hr after stimulation did not produce detectable amounts of CxRP. Inflamed muscle from the injection site did not show C(14)-amino acid incorporation into CxRP. Several human tissues were also cultured, and a few liver cultures found to contain labeled CRP. The formation of CxRP or CRP by the liver was always accompanied by enhanced C(14)-amino acid incorporation into other serum proteins, but the reverse was not always found.

Amino Acids↗
PubMed2006

Anodic asymmetry of leaves and flowers and its relationship to phyllotaxis.

BACKGROUND AND AIMS: New approaches are needed to evaluate the various hypotheses of phyllotaxis, and an examination of anodic leaf asymmetry may be one such approach. METHODS: Data were collected on the direction of midrib curvature and leaf coil in Syngonium podophyllum, the location of floral buds in Acalypha virginica, the position of secondary leaves of Croton variegatus 'Banana' and the relative size of half-lamina in Aglaonema crispum and Calathea ornata. KEY RESULTS: All five features were exclusively anodic with respect to the direction of the genetic spiral regardless of whether the spiral was clockwise or counterclockwise. CONCLUSIONS: Any phyllotactic mechanism must include some asymmetric component which cannot be explained by the prevalent hypotheses of contact parastichies, inhibitory fields, available space, pressure waves and auxin transport. The most favourable hypothesis is the primary vasculature explanation as it includes an asymmetric feature.

Araceae↗
PubMed1981

Co-carcinogenicity of promoting agents.

An experiment is described to investigate whether coadministration of a promoting agent would enhance the carcinogenicity of a repeatedly administered complete carcinogen. Topical application of the strong carcinogen 15,16-dihydro-11-methylcyclopenta[a]phenanthren-17-one (I) in toluene containing 1% v/v croton oil is about five times more effective than applications in toluene alone, as judged from the respective mean latent periods. A similar effect is also apparent for benzo[a]pyrene.

Animals↗
PubMed1982

Skin carcinogenesis and promoter binding characteristics in different mouse strains.

The sensitivity of various mouse strains to skin carcinogenesis has been investigated in two ways; (i) by comparing carcinogenesis induced by treatments involving both the application of tumour promoters and the application of single or multiple doses of a carcinogen, and (ii) by comparing the binding characteristics of the tumour promoter [3H]phorbol-12,13-dibutyrate to particulate skin preparations. The mouse strains tested were Swiss albino, Balb/c, C3H, LACA and AKR/J. Although some differences were apparent, Swiss albino, LACA and C3H mice were generally sensitive to skin carcinogenesis by both benzo[a]pyrene and 7,12-dimethylbenz[a]anthracene, either with or without promotion with croton oil. AKR/J mice were sensitive to both carcinogens with promotion but relatively insensitive in the absence of promotion. Balb/c mice had low sensitivity except when exposed to repeated low doses of benzo[a]pyrene. The [3H]phorbol-12,13-dibutyrate binding characteristics of particulate skin preparations from all strains were indistinguishable.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1975

Acetic acid, a potent stimulator of mouse epidermal macromolecular synthesis and hyperplasia but with weak tumor-promoting ability.

The effects of a single application of various dose levels of acetic acid or the weak tumor promoter, phorbol-12,13-ditetradecanoate, on the incorporation of tritiated thymidine (3H-TDR), 3H-cytidine, and 3H-leucine into DNA, RNA, and protein of mouse epidermis, respectively, were determined and compared with histologic changes in the skin. Treatment with either 500 or 833 mumoles acetic acid induced a sequential and sustained stimulation of RNA, protein, and DNA synthesis, which was followed by extensive epidermal hyperplasia similar to that reported for the strong promoter and irritant, 12-O-tetradecanoyl-phorbol-13-acetate. A dose-response relationship between the amount of acetic acid and the rate of DNA synthesis was found between the dose levels of 33 to 833 mumoles of acetic acid per application. The latter dose induced the maximum activation of 3H-TDR into DNA at 723% of control at 2 days, whereas 33 mumoles stimulated DNA synthesis earlier and peaked at 210% of control at 3 hours. Phorbol-12,13-ditetradecanoate also stimulated macromolecular synthesis in a similar sequence, though to a lesser degree. No observable inflammation and only a slight hyperplastic response were noted with phorbol-12,13-ditetradecanoate. Weekly applications of 667 mumoles of acetic acid produced a maximal tumor response of 0.73 papilloma/mouse after 32 weeks of promotion. However, a weekly dose of 677 mumoles of acetic acid was essentially inactive when given in two divided doses. When croton oil was administered twice weekly at a 0.25%-dose level, 10.2 papillomas/mouse were induced after 32 weeks of promotion. The results showed that the previously considered nonpromoting inflammatory agent, acetic acid, must be a weak promoter. However, there was no correlation between stimulated macromolecular synthesis or hyperplasia and tumor promotion when phorbol esters were compared with acetic acid.

Acetates↗
PubMed1977

Effect of trichloropropene oxide on the ability of polyaromatic hydrocarbons and their "K-region" oxides to initiate skin tumors in mice and to bind to DNA in vitro.

The potent epoxide hydrase inhibitor, 1,1,1-trichloro-2,3-propene oxide (TCPO), enhanced the tumor-initiating ability of benzo[alpha]pyrene (BP) and 3-methylcholanthrene (MCA) but had no effect on 9,10-dimethyl-1,2-anthracene (DMBA) initiation in a two-stage system of tumorigenesis in female Charles River CD-1 mice. The tumor-initiating ability of dibenz[alpha,h]-anthracene (DBA) was decreased by prior topical treatment with 10 mumoles of TCPO. The tumor latency period of BP and MCA was decreased by TCPO but had no effect on DMBA or DBA. Topical treatment with 10 mumoles of TCPO did not initiate tumors in a two-stage system in mouse skin nor did it cause any histopathologic changes in the skin. The "K-region" epoxides of BP, DMBA, and MCA were weak tumor initiators when compared to the parent compounds. TCPO only slightly increased or had no effect on the tumor-initiating activity of the above epoxides. Pretreatment with Croton oil 18 hours prior to initiation with BP-4,5-epoxide also slightly enhanced the tumorigenic response in mouse skin. DBA-5,6-epoxide, when tested as a complete carcinogen at high doses (1 mg daily/10 days), was found to be a weak carcinogen but with activity comparable to that of DBA. TCPO only slightly increased the in vitro epidermally mediated covalent binding of the above parent polycyclic hydrocarbons to DNA.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2000

Intestinal inflammation and morphine tolerance alter the interaction between morphine and clonidine on gastrointestinal transit in mice.

BACKGROUND: Morphine and clonidine show synergy or antagonism inhibiting gastrointestinal transit depending on their proportion and level of effect. Their interaction during morphine tolerance and intestinal inflammation were assessed. METHODS: Gastrointestinal transit in mice was evaluated with charcoal and antitransit effects expressed as percent mean values +/- SEM. Tolerance was induced with a morphine pellet (75 mg) implanted for 72 h, and inflammation with intragastric croton oil. Dose-response curves for morphine and clonidine alone and combined at a 1:1 potency ratio were obtained, and doses producing a 50% and 60% inhibition were calculated (ED50, ED60). Interaction was established by isobolograms, interaction indexes, and analysis of variance. RESULTS: In naive and tolerant mice, the combination induced linear dose-response curves up to the ED60 and then reached a plateau. In naive mice, ED50 values were as follows: morphine 1.52 +/- 0.15 mg/kg, clonidine 0.09 +/- 0.008 mg/kg, and combined 0.506 +/- 0.084 mg/kg (0.478 +/- 0.08 mg/kg morphine plus 0.028 +/- 0.004 mg/kg clonidine). During tolerance, ED50 values were as follows: morphine 9.73 +/- 0.8 mg/kg, clonidine 0.09 +/- 0.007 mg/kg, combination 0.131 +/- 0.09 mg/kg (morphine 0. 13 +/- 0.09 mg/kg plus clonidine 0.0013 +/- 0.0005 mg/kg). In both groups, the interaction was synergistic up to the ED60 and antagonistic thereafter; synergy was enhanced during tolerance. During inflammation, ED50 values were as follows: morphine 0.17 +/- 0.04 mg/kg, clonidine 0.015 +/- 0.006 mg/kg, combined 0.62 +/- 0.04 mg/kg (morphine 0.568 +/- 0.04 mg/kg plus clonidine 0.052 +/- 0.004 mg/kg); thus, potencies of morphine and clonidine increased 9.3 and 7.1 times, while the combination remained unaltered. Moreover, inflammation transformed synergy into antagonism. CONCLUSIONS: The interaction between morphine and clonidine was significantly altered during tolerance and inflammation. During tolerance, synergy was present up to 60% effect and then became antagonistic. Inflammation converted synergy to antagonism. A common pathway in signal transduction could partially explain the results.

Analgesics↗
PubMed1980

The influence of vitamin E on capsule formation and contracture around silicone implants.

An attempt was made to determine if the tissue response to surgical trauma and foreign body stimulus (silicone implants) could be altered using vitamin E in rats. The animals were divided into four groups: Group A served as controls, Group B were treated by intramuscular vitamin E, Group C were treated topically with vitamin E around the prosthesis, and Group D were treated topically with croton oil around the prosthesis. The animals in each group were killed at 2 week, 1 month, and 3 months intervals. The intraprosthetic pressure in each prosthesis was recorded using a strain gauge transducer. The capsules were then removed and examined histologically using a light microscope and the thickness of pseudocapsules was measured with an ocular micrometer. In Group B significantly thinner pseudocapsules were observed at 2 weeks, but there was no comparable difference either in thickness or degree of contracture (as measured by intraprosthetic pressures) between Groups A and B at 2 months and 3 months. In Group C, the pseudocapsules were significantly thicker at all tested periods and showed noticeable contracture at 3 months. In group D the pseudocapsules were thickest and cellular infiltrate more marked than in the other groups.

Administration, Topical↗
PubMed1987

The anatomy and histology of the anophthalmic socket--is the myofibroblast present?

For some anophthalmic patients, the contracted socket is a severe problem that precludes the wearing of a prosthesis. A normal and cosmetically acceptable appearance is dependent on the ability of a socket to retain a prosthesis. The disfigurement and distress caused by the contracted socket and its inability to accommodate a prosthesis may have a profound detrimental effect on the patient's career, self-esteem, and psychosocial interactions. The tissue dynamics at work in the anophthalmic socket and in the contracting socket are not yet understood. There are many unanswered questions regarding the histology and anatomy of the normal, as well as the contracting, socket. The tissue responsible for clinical contraction has not been identified. This thesis, using the cynomolgus monkey socket as an experimental model, investigated healing in both the normal and contracting socket. Qualitative observations of the anatomy and histology of eight sockets were made. Two of the sockets were treated with Croton oil to induce contractions. Biopsy specimens from two human sockets, one contracted and the other merely volume deficient, were also examined. Histopathology of the normal and contracting sockets were compared. Myosin subfragment 1 staining of actin for electron microscopy and immunoperoxidase staining of actin for light microscopy were performed on selected specimens. The myofibroblast, probably a modified fibroblast, is known to be present in the early stages of open wound healing and in contracting scar tissue elsewhere in the body. The myofibroblast has been incriminated as an agent generating contractile force. Under the conditions of this experiment, cells with the characteristics of myofibroblasts were identified by both immunoperoxidase staining and electron microscopy. They were found in healing noncontracting and contracting sockets. Cytoplasmic actin was also distinguished in arterioles, venules, capillaries, myoepithelial cells, smooth muscle, and skeletal muscle.

Actins↗
PubMed2006

Syntrophomonas cellicola sp. nov., a spore-forming syntrophic bacterium isolated from a distilled-spirit-fermenting cellar, and assignment of Syntrophospora bryantii to Syntrophomonas bryantii comb. nov.

A spore-forming, anaerobic, syntrophic fatty-acid-oxidizing bacterium, strain 19J-3(T), was isolated from a distilled-spirit-fermenting cellar in Hebei Province, China. The cells were slightly curved rods with a spore at the end of the cell. The optimal temperature for growth was around 37 degrees C and growth occurred in the range 25-45 degrees C. The pH range for growth was 6.5-8.5 and the optimum pH was 7.0-7.5. Crotonate was the only substrate that allowed the strain to grow in pure culture. However, the strain could oxidize saturated fatty acids with four to nine carbon atoms syntrophically in co-culture with Methanobacterium formicicum DSM 1535(T). The strain was not able to utilize sulfate, sulfite, thiosulfate, DMSO, nitrate, fumarate or Fe(III) as electron acceptor. The DNA base composition was 48.8 mol% G+C. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain 19J-3(T) was related to members of the family Syntrophomonadaceae and most closely to Syntrophospora bryantii DSM 3014(T) (94.3 % similarity) and Syntrophomonas wolfei subsp. wolfei DSM 2245(T) (93.6 % similarity). Considering the phylogenetic relationship and phenotypic features, strain 19J-3(T) (=CGMCC 1.5041(T)=JCM 13582(T)) is designated as the type strain of a novel species of the genus Syntrophomonas, Syntrophomonas cellicola sp. nov. Based on the close phylogenetic relationship between the genera Syntrophospora and Syntrophomonas, the presence of sporulation-specific genes in the genome of Syntrophomonas wolfei subsp. wolfei DSM 2245(T) and the description of a spore-forming member of Syntrophomonas, 'Syntrophomonas erecta subsp. sporosyntropha', we propose the assignment of Syntrophospora bryantii to the genus Syntrophomonas as Syntrophomonas bryantii comb. nov.

Alcoholic Beverages↗
PubMed2004

Metabolic properties of Eubacterium pyruvativorans, a ruminal 'hyper-ammonia-producing' anaerobe with metabolic properties analogous to those of Clostridium kluyveri.

Eubacterium pyruvativorans I-6(T) is a non-saccharolytic, amino-acid-fermenting anaerobe from the rumen, isolated by its ability to grow on pancreatic casein hydrolysate (PCH) as sole C source. This study investigated its metabolic properties and its likely ecological niche. Additional growth was supported by pyruvate, vinyl acetate, and, to a lesser extent, lactate and crotonate, and also by a mixture of amino acids (alanine, glycine, serine and threonine) predicted to be catabolized to pyruvate. No single amino acid supported growth, and peptides were required for growth on amino acids. Alanine, followed by leucine, serine and proline, were used most extensively during growth, but only alanine and asparate were extensively modified before incorporation. Growth on PCH, but not on pyruvate, was increased by the addition of acetate, propionate and butyrate. l-Lactate was fermented incompletely, mainly to acetate, but no lactate-C was incorporated. Propionate and butyrate were utilized during growth, forming valerate and caproate, respectively. Labelling experiments suggested a metabolic pattern where two C atoms of butyrate, valerate and caproate were derived from amino acids, with the others being formed from acetate, propionate and butyrate. The metabolic strategy of E. pyruvativorans therefore resembles that of Clostridium kluyveri, which ferments ethanol only when the reaction is coupled to acetate, propionate or butyrate utilization. The fermentative niche of E. pyruvativorans appears to be to scavenge amino acids, lactate and possibly other metabolites in order to generate ATP via acetate formation, using volatile fatty acid elongation with C(2) units derived from other substrates to dispose of reducing equivalents.

Adenosine Triphosphate↗
PubMed1985

Anti-inflammatory properties of an oxidized sterol.

A polar photoproduct of cholesterol oxidation, 7-ketocholesterol, was able to inhibit in a dose-dependent manner the mouse ear-swelling response to irritants such as croton oil or cantharidin. Its anti-inflammatory properties were much less than equivalent concentrations of hydrocortisone, but the oxidized sterol did not induce any systemic effects (as measured by thymolytic activity), as did topical hydrocortisone. It is concluded that 7-ketocholesterol has weak anti-inflammatory activity, and its mode of action may be different from that of glucocorticoids.

Administration, Topical↗
PubMed1993

Pentoxifylline suppresses irritant and contact hypersensitivity reactions.

Pharmacologic suppression of the effector phase of contact hypersensitivity appears to have major relevance with regard to treatment of type IV reactions like contact dermatitis. Recently, tumor necrosis factor alpha has been shown to be a critical mediator in hapten-induced irritant and contact hypersensitivity reactions, thus offering new possibilities, for therapeutic intervention. Pentoxifylline, a methylxanthine derivative used in the treatment of vascular disorders, currently has been found to suppress the production of tumor necrosis factor alpha by human and murine leukocytes. Therefore, the effect of pentoxifylline on the elicitation phase of contact hypersensitivity was studied. Intraperitoneal injection of pentoxifylline into sensitized Balb/c and C3H/HeN mice before application of the challenging hapten dose resulted in a significant reduction of the outcome of the contact hypersensitivity reaction. The suppressive effect of pentoxifylline was dose dependent and maximally pronounced upon injection 3 h before hapten application. In contrast to the effector phase of contact hypersensitivity, induction of contact hypersensitivity was not affected by pentoxifylline when injected into naive mice before performance of sensitization. In addition, irritant dermatitis induced by 1% croton oil or 5% benzalkonium chloride was suppressed by pentoxifylline as well. These data suggest a potential pharmacologic intervention, with pentoxifylline as a means to treat contact dermatitis.

Administration, Topical↗