Ontogeny of pepsinogen and gastric proton pump expression in red porgy (Pagrus pagrus): Determination of stomach functionality

The appearance of functionally developed gastric glands is commonly considered as the transition from the larval to the juvenile stage in fish, since it means the switch from the less efficient alkaline digestion to a more efficient acid digestion characteristic of adult specimens. From that moment, fish are supposedly able to better assimilate nutrients from inert diets. Acid digestion takes place by the action of pepsin activity and hydrochloric acid, both secreted by the gastric glands of the stomach. Pepsinogen is the precursor of pepsin which is converted into active enzyme by the action of hydrochloric acid secreted by the proton pump. The goal of this work was to asses the ontogeny of pepsinogen and gastric proton pump expression along larval development of red porgy using RT-PCR and in situ hybridization techniques. Firstly, red porgy specific pepsinogen and proton pump partial sequences were isolated. Amplification products presented 615 and 591 bp and were identified as pepsinogen IIb and the -subunit of the proton pump (H⁺/K⁺-ATPase) by sequencing, respectively. Both sequences were aligned to several predicted pepsinogen and proton pump polypeptides from different vertebrate species showing elevated homologies with them, especially in the case of the proton pump, the identity of which was never less than 90%. Pepsinogen and proton pump expressions were detected from 30 days post-hatching (dph), increasing with development. Proton pump expression was localized in the gastric glands of red porgy larvae as revealed by in situ hybridization, showing increasing signal intensity along the digestive system development. Such results indicated that at 30 dph red porgy starts to acquire the adult digestive capacity and therefore inert diets should be better utilized from that time onwards.     

Effect of water content on thermal behavior of freeze-dried soy whey and their isolated proteins

Thermal behavior of lyophilized soy whey (LSW) and whey soy proteins (WSP) at different water contents (WC) was studied by DSC. In anhydrous condition, Kunitz trypsin inhibitor (KTI) and lectin (L) were more heat stable for WSP with respect to LSW sample. The increase of WC destabilized both proteins but differently depending on the sample analyzed. Thermal stability inversion of KTI and L was observed for WSP and LSW at 50.0% and 17.0% WC, respectively, which correspond to the same water-protein content mass ratio (W/P ≈ 1.9). At W/P < 1.9, KTI was more heat stable than L. Before the inversion point, WC strongly modified the peak temperatures (T(p)) of KTI and L for WSP, whereas this behavior was not observed for LSW. The high sugar content was responsible for the thermal behavior of KTI and L in LSW under anhydrous condition and low WC. These results have important implications for the soy whey processing and inactivation of antinutritional factors.     

Identifying unique populations in long-dispersal marine species: Gulfs as priority conservation areas

Identification of areas which should be a subject of protection is crucial for safeguarding the marine ecosystems. Amongst the reasons for protecting a region or location, the existence of unique populations or evolutionary significant units for one or more key species is a priority. The North American silver hake, Merluccius bilinearis, is currently managed as two stocks (northern and southern) without considering gulf areas separately. Employing microsatellite and mitochondrial markers we have detected significant F_ST values between hake individuals inhabiting gulfs and those distributed in the open sea, and asymmetric gene flow, higher from the gulf to the open sea than in the opposite direction. These differences can be interpreted as signals of separate populations in gulfs which may act as sources of variability for hake species. Occurrence of similar phenomena in Atlantic waters in both the northern and the southern Hemisphere, for these two pelagic–demersal hake species, suggests that gulfs may constitute a target for designing marine protected areas and confirms the adequacy of gulf-specific management already employed in Argentina.     

Cochliomyia hominivorax myiasis in a colony of stray cats (Felis catus Linnaeus, 1758) in Rio de Janeiro, RJ

Cochliomyia hominivorax infestation in domestic cats of an urban colony in the city of Rio de Janeiro is described. The overall prevalence over the period 2001-2005 was 12.5%. Only adult cats were found infested and among these, most cases were observed in males (28%) (p < or = 0.05). The most frequently infested areas of the cats' bodies were the face and nape of the neck. Most lesions were found on the front part of the body of adult males (80%), suggesting that myiasis occur in consequence of competitive fighting wounds.     

Near-infrared spectroscopy in saffron quality control: determination of chemical composition and geographical origin

Near-infrared reflectance spectroscopy has been applied for the first time to saffron spice to determine the chemical composition and geographical origin of 111 samples from the there main producers' countries: Iran, Greece, and Spain. The validation procedures with the results obtained by UV-vis and HPLC-DAD measurements demonstrated that this technique is appropriate to determine the following parameters: moisture and volatile content, coloring strength, (250 nm), and (330 nm), established on the ISO 3632 Technical Specification Normative and used to certify saffron quality in the international market. Also, it can be used to estimate the content of the five main crocetin glycosides, the compounds responsible for saffron color, the best correlations being for trans-crocetin di-(beta-D-gentibiosyl) ester (R2= 0.93), trans-crocetin (beta-D-glucosyl)-(beta-D-gentibiosyl) (R2= 0.94), and picrocrocin (R2= 0.92), the compound accepted as responsible for saffron bitterness. Finally, a discriminant analysis among the three geographical origins reveals that Iranian samples are the most different, whereas Greek and Spanish samples are more similar. All of these results reveal that NIRS spectroscopy has an enormous potential for its application to saffron quality control as the results are obtained in 2 min and without any sample manipulation.     

MALDI-TOF, HPLC-ESI-TOF and 13C-NMR characterization of chestnut (Castanea sativa) shell tannins for wood adhesives

MALDI-TOF, HPLC-ESI-TOF and 13C-NMR techniques were used to analyse the structure of non-purified aqueous chestnut shell tannin extracts. In addition, the influence of the extraction agent (water or aqueous solutions of Na₂SO₃ and/or NaOH) on tannin structure was analysed by MALDI-TOF in order to select the extract with the best properties for wood adhesives. Using HPLC-ESI-TOF, catechin/epicatechin, gallocatechin/epigallocatechin, dicatechin structures, dicatechin structures without a hydroxyl group, galloyl-glucoses and ellagic acid were identified as the main monomeric components in the aqueous extract. 13C-NMR and MALDI-TOF spectra revealed that extracts are mostly composed of procyanidin and prodelphinidin structures although prorobinetidins might be also present. MALDI-TOF spectrometry was used to identify the extract oligomeric components. Extractions with Na₂SO₃ and/or NaOH produced changes in the predominant structures in the extracts and on the amount of sugar units linked to the flavonoid structures, which decreased in the presence of Na₂SO₃. Extract obtained using low Na₂SO₃ and NaOH concentrations (1.5 and 0.75 %, respectively) was selected as more suitable for wood adhesive preparation.