RESUMEN

The primary structure of syringicin (syr), a new acidic alpha-elicitin, isolated from culture filtrates of Phytophthora syringae, causal agent of citrus fruit rot, has been determined using a combined approch based on Edman degradation and MALDI-MS (TTCTT TQQTA AYVAL VSILS DSSFN QCATD SGYSM LTATA LPTTA QYKLM CASTA CKTMI TKIVS LNAPD CELTV PTSGL VLNVY SYANG FSSTC ASL). Syr has 98 amino acids with a M(r) of 10194.6+/-0.2, which was determined by electrospray ionisation-mass spectrometry (ES-MS) and in agreement with three disulphide bridges, located between Cys3-Cys71, Cys27-Cys56 and Cys51-Cys95. Syr induces a hypersensitive response and electrolyte leakage in tobacco. These are characteristic elicitor properties of the group and in agreement with the molecular mechanism recently proposed for this kind of protein. Finally, its possible applications in biological agriculture and biomedicine are briefly discussed.

Asunto(s)

RESUMEN

Elicitin 172, an acid protein with elicitor activity, has been isolated in true form from culture filtrates of Phytophthora nicotianae, the causal agent of crown and root rot of tomato (Lycopersicon esculentum). The M(r) (10,349 +/- 1) of the purified protein, determined by ES-MS, is identical to that calculated for parasiticein using the mean isotopic composition and assuming the occurrence of three disulfide bridges. The primary structure of elicitin 172, determined using also MALDI-MS experiments, shows complete identity with parasiticein, with elicitin 310 and a cloned elicitin gene from P. parasitica (= P. nicotianae), confirming conservation of the elicitin sequence within a single species. The protein induces necrosis (hypersensitive reaction) on tobacco, but no symptoms on tomato, when applied on the leaves. Tomato pretreated with elicitin 172 was affected by P. nicotianae, as well as by the phytotoxic aggregates, naturally occurring with the elicitin in the non permeated dialysis fraction of culture filtrates. Finally, the elicitin induce protection of capsicum (Capsicum annuum) and vegetable marrow (Cucurbita pepo) from P. capsici.

Asunto(s)

RESUMEN

The aim of this study was to describe and evaluate the laparoscopic treatment of esophageal achalasia in nine patients over a 35-month period. Five trocars were used to perform a Heller's myotomy to completely eliminate the cardial high-pressure zone, under manometric control. Intraoperative manometry also was used to calibrate a pick degrees 360 Rossetti's antireflux wrap. A complete regression of symptoms was observed postoperatively in seven of nine patients (77.8%); in two patients (22.2%) a moderate dysphagia persisted, but it disappeared 3 and 6 months, respectively. Only one intraoperative complication (esophageal perforation, recognized and laparoscopically repaired) occurred. At the present follow-up of 18 +/- 5.34 months (range 6-35), no dysphagia or symptoms related to reflux have been observed. Laparoscopic treatment of esophageal achalasia is considered a safe and effective procedure, and the results of this procedure are comparable with those of the open technique. Advantages common to other laparoscopic techniques are emphasized.

Asunto(s)

RESUMEN

The activity of cytochalasin B was tested on 8 Phytophthora species, while the same toxin, some of its derivatives and natural analogues, namely cytochalasin F and deoxaphomin, were assayed at 2 x 10(-5) - 2 x 10(-4) M on the most sensitive species, P. cactorum. A significant inhibitory activity on P. cactorum was shown by cytochalasin B, its 7-monoacetyl derivative, and deoxaphomin. The hydroxy group at C-20 and the conformational freedom of the macrocyclic ring proved to be important structural features for this activity. The 7-hydroxy group at C-7 appeared to have no influence on this toxicity, while a size reduction associated with the carbocyclic nature of the macrocycle seems to lightly increase the activity. The 7-O-acetylcytochalasin B showed selective toxic activity on P. cactorum at the tested concentration, thus suggesting a possible use as a fungicide for this compound.

Asunto(s)

RESUMEN

Olive oil vegetation waters (VW) were highly toxic to both phytopathogenic Pseudomonas syringae (Smith, Yung et al.) pv. savastanoi (Gram-negative) and Corynebacterium michiganense (Gram-positive) and showed bactericidal activity in their original concentration (in raw form). Among the main polyphenols, present in the waste waters, methylcatechol proved to be the most toxic to Ps. savastanoi at 10(-4) mol l-1, and also demonstrated bactericidal activity, while on Coryne. michiganense it was only slightly active; catechol and hydroxytyrosol were less active on Ps. savastanoi, but inactive on Coryne. michiganense; tyrosol and its synthetic isomers 1,2- and 1,3-tyrosol were completely inactive on both bacteria. Among the derivatives of VW polyphenols considered, acetylcatechol and guaiacol were selectively toxic for Ps. savastanoi, while o-quinone was strongly toxic for both bacteria. The minor carboxylic polyphenols of VW at 10(-4) mol l-1 were all inactive on the bacteria. VW, catechol, 4-methylcatechol and the less abundant carboxylic polyphenols proved to be toxic on Hep2 human cells. Finally the possibility of using the active polyphenols in agriculture in an integrated pest management program for the protection of the olive plant is discussed.

Asunto(s)

RESUMEN

Among the main polyphenols occurring in olive oil vegetation waters (VW), catechol showed the most deterrent action on the oviposition ofBactrocera oleae (Gmelin); 4-methylcatechol was less active, whereas hydroxytyrosol and tyrosol were inactive. In contrast, synthetico-quinone was found to be stimulant at 7.5 × 10(-2) M. Two other synthetic derivatives of catechol, diacetylcatechol and guaiacol, were also deterrent, suggesting these compounds undergo a biochemical transformation into catechol by means of the bacterial symbionts ofB. oleae. VW and their phenolic extracts showed deterrence only when highly concentrated, while natural olive juice was strongly deterrent. Experiments carried out to evaluate the effect of olive juice and catechol on the fecundity ofB. oleae showed that they strongly reduce this function. Moreover, the possible utilization of VW and their bioactive polyphenols in protection of olives againstBatrocera oleae is discussed.

RESUMEN

The problem of surgical fixing for incisional hernia is still far from a final solution. Over the past few years, prostheses have been used in addition to traditional plastic surgery. The aim of this experimental study was to assess the efficacy of traditional techniques in comparison to modern methods using prostheses. For this purpose, two original experimental models were designed to assess parietal resistance. Ninety-six Wistar rats were subdivided into 4 group: 1) control; 2) "waistcoat" plastic surgery; 3) plastic surgery using a vicryl prosthesis. With the exception of rats in group 1, a lozenge-shaped section of abdominal wall was removed from all other rats and, subsequently, the wall was repaired using the above-mentioned methods. Rats were killed after 30-60-120-180 days and the abdominal walls were subjected to traction and pressure using specially designed experimental models. For the first 30 days, the walls with dacron and vicryl prostheses behaved in a similar way, and showed a greater resistance than the other two groups; but after day 120, the resistance of dacron prostheses was considerably greater than that of the other groups studied. In conclusion, plastic surgery based on the use of nonreabsorbable prostheses is now more efficacious than traditional plastic surgery in the surgical treatment of incision hernia.

Asunto(s)

RESUMEN

Mezlocillin is a new acyl-ureido-penicillin with a broad spectrum of action, particularly directed against Gram-negative bacteria, including Pseudomonas aeruginosa. The therapeutic efficacy of this new antibiotic was assayed in 20 patients affected by serious biliary tract infections. Complete recovery was reached in 80% of the patients. Such a recovery rate is very high, considering the type of infectious pathology. Furthermore, the pharmacokinetics of mezlocillin was followed in the bile, as well as in the wall of the gallbladder, in gall-stones and in serum after single or repeated administration of the drug; the results favored the therapeutic use of mezlocillin. It is concluded that mezlocillin is a first choice antibiotic in the treatment of biliary tract infections.

Asunto(s)

Asunto(s)

Asunto(s)