Overexpression of the carbohydrate binding module from Solanum lycopersicum expansin 1 (Sl-EXP1) modifies tomato fruit firmness and Botrytis cinerea susceptibility.

Firmness, one of the major determinants of postharvest quality and shelf life of fruits is determined by the mechanical resistance imposed by the plant cell wall. Expansins (EXP) are involved in the non-hydrolytic metabolic disassembly of plant cell walls, particularly in processes where relaxation of the wall is necessary, such as fruit development and ripening. As many carbohydrate-associated proteins, expansins have a putative catalytic domain and a carbohydrate-binding module (CBM). Several strategies have been pursued to control the loss of fruit firmness during storage. Most of the approaches have been to suppress the expression of key enzymes involved in the cell wall metabolism, but this is the first time that a CBM was overexpressed in a fruit aimed to control cell wall degradation and fruit softening. We report the constitutive overexpression of the CBM of Solanum lycopersicum expansin 1 (CBM-SlExp1) in the cell wall of tomato plants, and its effects on plant and fruit phenotype. Overexpression of CBM-SlExp1 increased the mechanical resistance of leaves, whereas it did not modify plant growth and general phenotype. However, transgenic plants showed delayed softening and firmer fruits. In addition, fruits were less susceptible to Botrytis cinerea infection, and the "in vitro" growth of the fungus on media containing AIR from the pericarp of transgenic fruits was lower than controls. The possibility of overexpressing a CBM of a fruit-specific expansin to control cell wall degradation and fruit softening is discussed.

Analysis of the carbohydrate-binding-module from Fragaria x ananassa α-L-arabinofuranosidase 1.

α-L-arabinofuranosidases (EC 3.2.1.55) are enzymes involved in the catabolism of several cell-wall polysaccharides such as pectins and hemicelluloses, catalyzing the hydrolysis of terminal non-reducing α-L-arabinofuranosil residues. Bioinformatic analysis of the aminoacidic sequences of Fragaria x ananassa α-L-arabinofuranosidases predict a putative carbohydrate-binding-module of the family CBM_4_9, associated to a wide range of carbohydrate affinities. In this study, we report the characterization of the binding affinity profile to different cell wall polysaccharides of the putative CBM of α-L-arabinofuranosidase 1 from Fragaria x ananassa (CBM-FaARA1). The sequence encoding for the putative CBM was cloned and expressed in Escherichia coli, and the resultant recombinant protein was purified from inclusion bodies by a Nickel affinity chromatography under denaturing conditions. The refolded recombinant protein was then subjected to binding assays and affinity gel electrophoresis, which indicated its ability to bind cellulose and also high affinity for homogalacturonans.

Thoracic complications in patients undergoing intraperitoneal heated chemotherapy with mitomycin following cytoreductive surgery.

BACKGROUND: The purpose of this study was to determine the incidence and severity of thoracic reactions in patients undergoing intraperitoneal heated chemotherapy (IPHC). METHODS: Forty-two patients who had intraperitoneal disseminated malignancies were treated with cytoreductive surgery (CS) and IPHC. The primary malignancies included carcinoma of the colon (n = 17), stomach (n = 6), appendix (n = 6), pseudomyxoma peritonei (n = 3), mesothelium (n = 2), ovaries (n = 2), jejunum (n = 2), gallbladder (n = 1), urachus (n = 1), and peritoneal carcinomatosis (n = 2). After CS, IPHC with mitomycin (MMC) was administered by perfusion at 40.5 degrees C. After IPHC, multiple radiographs of the chest were reviewed in comparison to the control group. RESULTS: Thoracic complications occurred in 36 patients (86%), including atelectasis in 32 patients (76%), pleural effusions in 27 (64%), pulmonary edema in 10 (24%), pneumonia in 2 (5%), and pneumothorax in 2 (5%). The incidence of thoracic complications in the IPHC group was significantly higher than that of patients in the control group (P < .05). Correlations between the prevalence of pleural effusion and the dose of MMC, duration of procedure, and presence of thrombocytopenia were not significant (P > .05). CONCLUSIONS: Bibasilar atelectasis and pleural effusions are common findings after IPHC with MMC, but most of them do not necessarily warrant intervention.

Sound production evoked by electrical stimulation of the forebrain in the oyster toadfish.

In mammals, birds and amphibians the neural pathways controlling sound production descend from higher centers in the forebrain, whereas in fishes only brainstem and spinal centers have been explicitly implicated in sound production. We now report that electrical stimulation of the forebrain of the oyster toadfish (Opsanus tau) readily evokes both the agonistic grunt and the courtship boatwhistle. Boatwhistles are more realistic than ones previously evoked from lower centers. Positive stimulation sites are localized in the preoptic area (nucleus preopticus parvocellularis anterior) and the supra-commissural nucleus of the ventral telencephalon, a likely homologue of the amygdala. Both sites contain gonadal steroid-concentrating neurons and play a central role in fish courtship behavior. Evoked sounds form a continuum from knock grunts, burst grunts, transition boatwhistles to complete boatwhistles; sound pressure level (SPL), fundamental frequency and duration increase consistently within the continuum. For all sound types, SPLs exhibit the smallest variation (coefficients of variation of 2.7 to 5.7%), fundamental frequency is intermediate (5 to 13%) and durations vary most widely (18 to 60%). Boatwhistles, with the smallest variation and greatest amplitude, are likely generated by a maximal output of the CNS and sonic muscles. Grunt SPLs however, vary over a range of 26 dB for all fish and by as much as 18 dB in an individual; suggesting recruitment of variable numbers of motor units despite electrical coupling within the sonic motor nucleus.