Salicylic Acid Induces Changes in Mango Fruit that Affect Oviposition Behavior and Development of the Oriental Fruit Fly,Bactrocera dorsalis

The Oriental fruit fly, Bactrocera dorsalis (Hendel) is an important quarantine pest around the globe. Although measures for its control are implemented worldwide through IPM and male annihilation, there is little effect on their population. Hence, there is a need for new strategies to control this minacious pest. A strategy that has received negligible attention is the induction of ‘natural plant defenses’ by phytohormones. In this study, we investigated the effect of salicylic acid (SA) treatment of mango fruit (cv. Totapuri) on oviposition and larval development of B. dorsalis. In oviposition choice assays, gravid females laid significantly less eggs in SA treated compared to untreated fruit. Headspace volatiles collected from SA treated fruit were less attractive to gravid females compared to volatiles from untreated fruit. GC-MS analysis of the headspace volatiles from SA treated and untreated fruit showed noticeable changes in their chemical compositions. Cis-ocimene and 3-carene (attractants to B. dorsalis) were reduced in the headspace volatiles of treated fruit. Further, reduced pupae formation and adult emergence was observed in treated fruit compared to control. Increased phenol and flavonoid content was recorded in treated fruit. We also observed differential expression of anti-oxidative enzymes namely catalase (CAT), polyphenoloxidase (PPO) and peroxidase (POD). In summary, the results indicate that SA treatment reduced oviposition, larval development and adult emergence of B. dorsalis and suggest a role of SA in enhancing mango tolerance to B. dorsalis.     

Activation of the IGF1 system characterizes cholangiocyte survival during progression of primary biliary cirrhosis.

We evaluated the IGF1 system in cholangiocytes of primay biliary cirrhosis (PBC) patients and investigated the relationships with apoptosis. Biopsies of PBC patients (n=32) and normal subjects (n=5) were investigated by immunohistochemistry for expression in cholangiocytes of IGF1, IGF1-R, pAKT, terminal deoxynucleotide transferase end labeling (TUNEL), Bax (proapoptotic protein), and Bcl2 (antiapoptotic protein). Whereas normal cholangiocytes were almost negative, cholangiocytes of PBC patients showed strong IHC staining for IGF1, IGF1-R, and pAKT, which increases from stage I to stage IV, where >70% of cholangiocytes were positive. Bax/Bcl2 ratio reached the highest value (4.6) in PBC stage III when apoptosis is maximal (24% TUNEL positivity), whereas it declines in stage IV (1.4) when only 7.8% cholangiocytes were TUNEL positive. In PBC stages III and IV, expression of IGF1, IGF1-R, and pAKT in cholangiocytes was directly correlated with the antiapoptotic Bcl2 and inversely correlated with proapoptotic Bax, Bax/Bcl2 ratio, and TUNEL positivity. In conclusion, cholangiocytes of PBC patients showed a marked increase in IGF1, IGF1-R, and pAKT expression involving most cholangiocytes surviving in the terminal ductopenic stage. This was associated and correlated with a balance of pro- and antiapoptotic proteins favoring survival rather than apoptosis, suggesting a major role of IGF1 system in promoting cholangiocyte survival.     

Anaesthetic Tricaine Acts Preferentially on Neural Voltage-Gated Sodium Channels and Fails to Block Directly Evoked Muscle Contraction

Movements in animals arise through concerted action of neurons and skeletal muscle. General anaesthetics prevent movement and cause loss of consciousness by blocking neural function. Anaesthetics of the amino amide-class are thought to act by blockade of voltage-gated sodium channels. In fish, the commonly used anaesthetic tricaine methanesulphonate, also known as 3-aminobenzoic acid ethyl ester, metacaine or MS-222, causes loss of consciousness. However, its role in blocking action potentials in distinct excitable cells is unclear, raising the possibility that tricaine could act as a neuromuscular blocking agent directly causing paralysis. Here we use evoked electrical stimulation to show that tricaine efficiently blocks neural action potentials, but does not prevent directly evoked muscle contraction. Nifedipine-sensitive L-type Ca_v channels affecting movement are also primarily neural, suggesting that muscle Na_v channels are relatively insensitive to tricaine. These findings show that tricaine used at standard concentrations in zebrafish larvae does not paralyse muscle, thereby diminishing concern that a direct action on muscle could mask a lack of general anaesthesia.     

Radioimmunodetection of melanoma: preliminary results of a prospective study

A prospective study to evaluate the clinical usefulness of radioimmunodetection of melanoma in clinical practice is ongoing at the National Cancer Institute of Milan, Italy. Technical conditions for the application of the method were previously reported. In this trial, 99mTc-labelled F(ab')2 fragments of the 225.28S monoclonal antibody were used against a high molecular weight melanoma associated antigen (HMW-MAA). Retrospective studies on radioimmunodetection of melanoma have already been made by our group and by other Centers in about 300 patients. This study concerns the evaluation of the regional extension of primary melanoma. 23 patients with 32 suspected lymphatic involvements of melanoma on the trunk and arms underwent immunoscintigraphy. No false positive results were observed; 3 false negatives, one corresponding to a micrometastasis, were noticed. Specificity corresponds to 100% and sensitivity to 78.6%.     

Hepatic 3 alpha-dehydrogenation and 7 alpha-hydroxylation of deoxycholic acid in the guinea-pig

The metabolic fate of exogenous deoxycholate administered either intraperitoneally or intragastrically to male Hartley guinea-pigs was investigated. Two animals received a constant infusion of [24-14C]deoxycholate through an intraperitoneal catheter for 2 hr. Bile was quantitatively collected in 30 min samples during infusion and for 2 additional hours. Each bile sample was analyzed for composition and radioactivity. Five animals received for 15 days, through an intragastric catheter, 35 mg/kg/day of deoxycholate. The biliary bile acid composition was compared with that of a sham-operated control group. The studies with both animal models indicated that guinea-pigs, as the only species so far known, extensively oxidize deoxycholate to form 3-oxo,12 alpha-hydroxy-cholanic acid, which is secreted in bile mostly conjugated with glycine. In addition a small fraction (approx. 7%) of the administered deoxycholate is 7 alpha hydroxylated to form cholic acid. The metabolites being more hydrophilic than administered deoxycholate, it is suggested that guinea-pig liver counteracts the adverse increase in bile acids detergency, which follows deoxycholate administration, by converting most of the latter into less detergent compounds.     

Relationships between bile salts hydrophilicity and phospholipid composition in bile of various animal species

Bile salts and phospholipids from bile of chicken, dog, sheep, rat, ox, pig, guinea-pig and man were analyzed by high-performance liquid chromatography. Bile salts showed marked differences in their hydrophilic properties, owing to hydroxyl structure and type of conjugation. Phospholipids were generally similar, containing 90-95% of phosphatidylcholine which was made of molecular species containing palmitic acid in the sn-1 position. The comparative analysis of bile salts and phosphatidylcholines profile demonstrated that bile salts hydrophilicity influences the quantity of phosphatidylcholine in bile but not the quality.     

Monoamine oxidase and transaminase screening: biotransformation of 2-methyl-6-alkylpiperidines by <Emphasis Type="Italic">Neopestalotiopsis</Emphasis> sp. CBMAI 2030

High-throughput screening detected transaminases (TAs) and monoamine oxidases (MAOs) in fungi by applying a fluorogenic probe. Strains F026, F037, F041, F053, and F057 showed the highest enzymatic conversions (31, 60, 30, 40, and 32%, respectively) and where evaluated for their ability to transform piperidines. Strain F053 (Neopestalotiopsis sp. CBMAI 2030) revealed unusual enzymatic activity to deracemize 2-methyl-6-alkylpiperidines. Neopestalotiopsis sp. CBMAI 2030 was capable to convert 2-methyl-6-propylpiperidine, 2-methyl-6-butylpiperidine, and 2-methyl-6-pentylpiperidine in piperideine with 11, 14, and 24% conversion, respectively. The activity was enhanced by cultivating the fungus with 2-methyl-6-pentylpiperidine (38% conversion and 73% ee).     

Prokaryotic expression of the thyrotropin receptor and identification of an immunogenic region of the protein using synthetic peptides

Graves' disease is characterized by hypersecretion of thyroid hormones due to binding of autoantibodies to the thyrotropin receptor (TSHR). In order to study immunological aspects of the TSHR we expressed the extracellular domain of the rat TSHR (ETSHR) as a fusion protein with beta-galactosidase in a prokaryotic system. The identity of this ETSHR-fusion protein was confirmed by Western blot, using antibodies to synthetic peptides derived from TSHR. Patients' sera reacted to a significantly greater extent with the affinity purified ETSHR relative to control sera. Similarly, sera from patients with Graves' disease displayed significant reactivity with only one of five peptides, RH2 (residues 352-366), when compared with normal sera. These data, together with the predicted hydrophilicity of the peptide RH2, suggest that amino acids 352-366 which lie within one of the unique regions of the extracellular domain of the TSHR may be important for antibody binding.     

Biliary secretion of phosphatidylcholine and its molecular species in cholecystectomized T-tube patients: effects of bile acid hydrophilicity

The aim of the present study was to establish whether the oral administration of bile acids with different hydrophilic properties affects the amount of phosphatidylcholine as well as the pattern of PC molecular species secreted in bile. We studied the biliary output of total and individual PC species in cholecystectomized T-tube patients, with a total biliary outflow, after oral administration of 750 mg of ursodeoxycholate (3 patients) or deoxycholate (3 patients). The latter experiments were repeated after 3 days of taurine supplementation (1500 mg daily) in order to increase, by means of the tauro-conjugation, the hydrophilicity of the secreted BA. A linear function was observed, during all the studies, between BA and PC biliary secretion, but the amount of PC secreted per mole of BA was higher for the less hydrophilic BA, such as deoxycholate, than for the more hydrophilic ursodeoxycholate or during deoxycholate plus taurine experiments. With regard to the pattern of PC molecular species, we observed no changes after administration of ursodeoxycholate. An increase in the secretion of the major polyenoic species (i.e., 16:0-18:2 and 16:0-20:4), with respect to the secretion of the monoenoic, was revealed during deoxycholate experiments. Conversely, during the deoxycholate plus taurine experiments, the secretion of the major monoenoic PC species (i.e., 16:0-18:1) increased more than that of the polyenoic species. We suggest that the observed modifications of the pattern of PC molecular species, secreted in bile, represent the result of a physicochemical effect of BA on liver membranes.