Feed pellets containing chitosan nanoparticles as plasmid DNA oral delivery system for fish: In vivo assessment in gilthead sea bream (Sparus aurata) juveniles.

The aim of this study was the assessment of preloaded feed pellets as a delivery system for plasmid DNA (pDNA), with the purpose of evaluating the potential administration of DNA vaccines orally in aquacultured fish. Pellets were made up by usual feed ingredients, which were mixed with chitosan nanoparticles entrapping a model plasmid (pCMVß) expressible in eukaryotic cells before being elaborated. The plasmid is characterized by the insertion of the reporter gene lacZ, encoding for the bacterial enzyme ß-galactosidase (ß-gal). The possible in vivo expression of the exogenous gene was measured in different fish tissues of gilthead sea bream (Sparus aurata) juveniles by two different procedures. On the one hand, the activity of the enzyme ß-gal was detected and quantified in muscle, liver and intestine; on the other, specific IgM against ß-gal antigen was titrated in blood samples. Intramuscular (i.m.) injection of equal amounts of plasmid was also carried out for the purpose of comparison with oral administration. The expression of the reporter gene was detected in fish tissues following both oral and i. m. administration of pDNA up to 60 days. However, organ distribution of the gene expression was more evident after oral (ß-gal activity measured in gut, liver and muscle) than after parenteral administration (restricted to adjacent muscle tissues). In agreement, specific IgM titration indicated that humoral immune response was more intense and sustained throughout the experimental period after oral than after i. m. delivery of equal amounts of pDNA. These results suggest that feed pellets containing chitosan nanoparticles might enable efficient oral delivery of pDNA, a fact that might imply valuable applications in terms of on-farm mass immunization purposes, especially with regard to DNA-based vaccines and small size fish, in which i. m. administration remains unfeasible.

Digestive enzyme activities during early ontogeny in Common snook (Centropomus undecimalis).

Common snook (Centropomus undecimalis) is one of the most important marine species under commercial exploitation in the Gulf of Mexico; for this reason, interest in developing its culture is a priority. However, larviculture remains as the main bottleneck for massive production. In this sense, our objective was to determine the changes of digestive enzymes activities using biochemical and electrophoretic techniques during 36 days of Common snook larviculture fed with live preys (microalgae, rotifers, and Artemia). During larviculture, all digestive enzymatic activities were detected with low values since yolk absorption, 2 days after hatching (dah) onwards. However, the maximum values for alkaline protease (6,500 U mg protein(-1)), trypsin (0.053 mU × 10(-3) mg protein(-1)), and Leucine aminopeptidase (1.4 × 10(-3) mU mg protein(-1)) were detected at 12 dah; for chymotrypsin at 25 dah (3.8 × 10(-3) mU mg protein(-1)), for carboxypeptidase A (280 mU mg protein(-1)) and lipase at 36 dah (480 U mg protein(-1)), for α-amylase at 7 dah (1.5 U mg protein(-1)), for acid phosphatases at 34 dah (5.5 U mg protein(-1)), and finally for alkaline phosphatase at 25 dah (70 U mg protein(-1)). The alkaline protease zymogram showed two active bands, the first (26.3 kDa) at 25 dah onwards, and the second (51.6 kDa) at 36 dah. The acid protease zymogram showed two bands (RF = 0.32 and 0.51, respectively) at 34 dah. The digestive enzymatic ontogeny of C. undecimalis is very similar to other strictly marine carnivorous fish, and we suggest that weaning process should be started at 34 dah.

Shape at the cross-roads: homoplasy and history in the evolution of the carnivoran skull towards herbivory.

Patterns of skull shape in Carnivora provide examples of parallel and convergent evolution for similar ecomorphological adaptations. However, although most researchers report on skull homoplasies among hypercarnivorous taxa, evolutionary trends towards herbivory remain largely unexplored. In this study, we analyse the skull of the living herbivorous carnivorans to evaluate the importance of natural selection and phylogenetic legacy in shaping the skulls of these peculiar species. We quantitatively estimated shape variability using geometric morphometrics. A principal components analysis of skull shape incorporating all families of arctoid carnivorans recognized several common adaptations towards herbivory. Ancestral state reconstructions of skull shape and the reconstructed phylogenetic history of morphospace occupation more explicitly reveal the true patterns of homoplasy among the herbivorous carnivorans. Our results indicate that both historical constraints and adaptation have interplayed in the evolution towards herbivory of the carnivoran skull, which has resulted in repeated patterns of biomechanical homoplasy.

Digestive proteases during development of larvae of red palm weevil, Rhynchophorus ferrugineus (Olivier, 1790) (Coleoptera: Curculionidae).

The evolution of digestive proteases during larval development of Rhynchophorus ferrugineus (Olivier, 1790) has been studied. A progressive increase of protease activity has been found. The optimum pH for proteolytic activity against azocasein was determined. Caseinograms revealed an active complex of alkaline proteases from the early stages of the development. From the apparent molecular masses, three groups of proteases have been found - high molecular-mass proteases, medium molecular-mass proteases, and low molecular-mass proteases. Studies using specific protease inhibitors showed the major presence of serine proteases in gut extracts. The results obtained from larvae reared on different substrates have made possible a comparative assessment of the influence of diet on the development of the digestive enzymatic system. Larvae fed on an artificial diet showed a complete pattern of digestive proteases. Data suggest that this diet seems to be suitable for future research with this insect pest.

Improved detection of amylase activity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with copolymerized starch.

An improved method, based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for detection of amylase activity is described. This method will allow better characterization of certain amylases than that obtained by the Davis technique. The main features of the technique are: (i) identification of amylase bands and molecular mass determination are possible in the same gel; (ii) the hydrolysis of copolymerized substrate during electrophoretic separation is prevented using very low temperatures instead of inactivating agents such as chelating agents; and (iii) the technique is applicable to reveal amylase activity in a wide range of biological samples. The method is not useful for enzymes sensitive to SDS and for high molecular mass amylases.

Familial adenomatous polyposis: efficacy of endoscopic and surgical treatment for advanced duodenal adenomas.

INTRODUCTION: Duodenal and periampullary cancer is the most common cause of cancer death in patients with familial adenomatous polyposis who have undergone colectomy. Endoscopic surveillance of upper gastrointestinal adenomas is recommended for patients with familial adenomatous polyposis but the timing and appropriate treatment of neoplasms is unknown. The purpose of this experiment was to report our experience with endoscopic and surgical treatment of advanced duodenal adenomas in patients with familial adenomatous polyposis. METHODS: The records of all patients with familial adenomatous polyposis who had undergone surgical or endoscopic treatment for duodenal adenomas were identified. Data including endoscopic surveillance findings, type of intervention, pathology, and follow-up of the lesions were reviewed. RESULTS: Ten neoplasms >1 cm were treated in eight patients (mean age at the time of diagnosis was 49 years). Nine lesions were histologically advanced. Five lesions involved the papilla. Endoscopic treatment was performed for six lesions. Four lesions recurred, and three were then treated surgically. Local resection was performed for five lesions. Four lesions recurred and two had further operative intervention. Pancreas-sparing duodenectomy was performed in three patients. At a mean follow-up period of 45.7 months, there has been no recurrence. CONCLUSIONS: Endoscopic eradication is an appropriate initial treatment for histologically advanced, noncancerous neoplasms or for patients who are not surgical candidates. Pancreas-sparing duodenectomy may be the treatment of choice for patients with carcinoma and those who have failed endoscopic therapy.

Diagnosing and treating depression in primary care patients: looking beyond physical complaints.

Depression is common, but often overlooked because patients with depression often present with somatic complaints rather than psychological ones. Primary care physicians must learn to recognize depression and be thoroughly familiar with its treatment, because this disease is common and serious.

Partition coefficients of alpha-amylase in aqueous two-phase systems PEG + MgSO4.7H2O + H2O at 298 K.

Partition coefficients of alpha-amylase have been determined in a polyethylene glycol (average molecular mass 8000)/MgSO4.7H2O aqueous two-phase system at 298 K and the influence of polymer, salt and initial enzyme concentration on partition was investigated. Correlations are proposed which relates the partition coefficient to the initial enzyme concentration and the concentration difference between phases of polymer and salt. The free volume change, related to the densities of the separate phases, has a direct dependence with such polymer and salt concentration differences, respectively, and is then used to facilitate future estimations. Thus, the partition coefficient is a function of this physical parameter and the initial enzyme concentration employed (1.25, 2.50 and 5.00 g dm-3).

Ovotestis variability in young and adult females of the mole Talpa occidentalis (insectivora, mammalia).

The age-related evolution and ontogenic origin of the ovotestes in fertile females of the Spanish mole (Talpa occidentalis) were studied. Volume of the ovotestis and its ovarian and testicular components, size of the epididymis and testicular cords, number of ovarian follicles and testicular cords, uterus weight, and age index were analyzed statistically in a large sample of young and adult individuals of this species. Comparison of means and linear correlation analyses were done. Most variables were shown to be age dependent, with a period of rapid change during puberty. In adult animals, volume of the ovarian portion and uterus weight followed a seasonal cycle of sexual activity. Interindividual variability was evident in most of the variables investigated except for the number of testicular cords per ovotestis, which remained unchanged throughout the animal's life and hence was not inversely correlated with the number of ovarian follicles. This finding ruled out an ovary-testis transdifferentiation hypothesis for the ontogenic origin of the testicular tissue in the ovotestes of female moles. An alternative hypothesis based in the absence of oocytes in a portion of the undifferentiated fetal gonad is proposed in accordance with a new general model for mammalian sex determination.

Characterization of digestive enzyme activity during larval development of gilthead seabream (Sparus aurata).

The evolution of the digestive enzyme equipment in seabream from hatching to 30 days old larvae was studied; there was a progressive increase in the activity of protease, amylase and acid and alkaline phosphatase from day 15 onwards. The use of specific inhibitors, and SDS-PAGE provided evidence to suggest that most of the proteases belonged to the serine group. A high α-amylase activity was also denoted. Zymograms of larval extracts indicated that exogenous food has more a qualitative than a quantitative role in the secretion of digestive enzymes in this species.

Fertile females of the mole Talpa occidentalis are phenotypic intersexes with ovotestes.

We investigated the origin of XX sex reversal in the insectivorous mole Talpa occidentalis. Cytogenetic, histological and hormonal studies indicate that all XX individuals analyzed from two different populations are true hermaphrodites, with ovotestes. This suggests that XX sex reversal may be the norm in this species. The intersexes are functional fertile females and the trait is transmitted and maintained in the population. Intersexes lack the Y chromosome gene SRY (sex determining region Y gene), shown to be the testis determining gene. These results suggest that XX intersex moles may have arisen from a mutation of a gene located downstream from SRY/TDY in the testis determining pathway.

[Acute renal insufficiency secondary to ureteral obstruction]. / Insuficiencia renal aguda secundaria a obstrucción ureteral.

Acute renal insufficiency due to ureteral obstruction is relatively uncommon and gives rise to difficulties of diagnosis and treatment. The series presented here analyzes these aspects in 24 patients who had 27 episodes of proven anuria due to ureteral obstruction. Their average age was 62. Six patients had only one kidney (25%). The most common etiology was cancer (two thirds of the cases), mainly of genitourinary origin (10/16). Calcium or uric acid urethral lithiasis was the main cause of obstruction in the benign group. Treatment corresponded to a wide range of obstruction removal procedures depending on the etiology, but in the secondary to cancer it was very aggressive and the most used was nephrostomy. The decision to perform any treatment of obstructive anuria in patients with cancer should take into account a variety of important aspects amongst which prevail the prognosis of the basal illness, the handling of cancerous pain, the complications and mortality associated with the procedure and the patient's prospects.

Acute rhabdomyolysis associated with cocaine intoxication.

Because an increasing number of patients were arriving at our emergency room with cocaine intoxication and rhabdomyolysis, we reviewed our experience with such patients. We identified 39 patients seen at our institution over an eight-year period with acute rhabdomyolysis after cocaine use. The patients' mean creatine kinase level was 12,187 U per liter (range, 1756 to 85,000). Thirteen of the 39 patients (33 percent) had acute renal failure; 6 of them died. In comparison to the patients with normal renal function, those with renal failure were more often admitted with profound hypotension (46 vs. 4 percent; P less than 0.001), hyperpyrexia (69 vs. 15 percent; P less than 0.001), and markedly elevated serum creatine kinase levels (mean, 28,084 vs. 7931 U per liter; P less than 0.01). Disseminated intravascular coagulation developed in seven patients with renal failure. All six deaths were in this group. Severe hepatic dysfunction was found in 11 patients with renal failure. We conclude that cocaine intoxication can cause acute rhabdomyolysis with acute renal failure, severe liver dysfunction, and disseminated intravascular coagulation and that the mortality rate among patients with this syndrome is high.