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Biomedical subjects

D Castro

Publications and source records attributed to D Castro.

At least 19 recordsLinked to original sources
PubMed2002

Vibrios isolated from the cultured manila clam (Ruditapes philippinarum): numerical taxonomy and antibacterial activities.

AIMS: A numerical taxonomic study of halophilic Vibrio isolated from healthy and brown ring disease (BRD) affected manila clams (Ruditapes philippinarum), harvested from the Atlantic coast of south-western Spain, was performed. METHODS AND RESULTS: Characterization of 123 presumptive Vibrio spp. was carried out using 94 phenotypic tests. Simple matching and Jaccard similarity coefficients were used for numerical analysis. Cluster analysis by the unweighted pair group method with arithmetic averages yielded 15 phena defined at 0.81 similarity. Large phena corresponded to Vibrio tubiashii, V. splendidus biotype I and V. harveyi (phena 1, 5 and 9, respectively). The species V.splendidus biotype II, V. natriegens, V. mediterranei and V. alginolyticus were also represented. The inhibitory effect of diffusible extracellular products of the isolates against 27 strains of V.tapetis, the aetiological agent of BRD, was also investigated. Only five V. tubiashii isolates inhibited the growth of V. tapetis strains. The antimicrobial effect was inhibited by heating and depended on the culture medium. CONCLUSIONS: The main Vibrio species associated with manila clams were V. tubiashii, V.spendidus and V. harveyi. The antagonistic relationship established between V. tapetis and the Vibrio spp. clam microbiota may explain the failure of isolation in plating medium of V.tapetis from BRD-affected clams on the south Atlantic coast of Spain. SIGNIFICANCE AND IMPACT OF THE STUDY: Some of the strains isolated from manila clams correspond to agarolytic strains that constitute phenon 7 and they do not fit into any of the currently described Vibrio species.

Animals↗
PubMed2001

Antigenic properties and experimental transmission to several fish species of a marine birnavirus isolated from sole (Solea senegalensis).

A cross-neutralization test was used to study the antigenic relationship of an aquabirnavirus isolated from sole (Solea senegalensis), named solevirus, and several infectious pancreatic necrosis virus (IPNV) strains. Solevirus was antigenically similar to IPNV strain Sp. Transmission of the solevirus to other fish species has been determined by inoculation to freshwater and marine fish species (two salmonids and gilt-head seabream). A higher pathogenicity was obtained for the marine fish species, although solevirus caused an asymptomatic infection in all species tested, as demonstrated by the detection of viral RNA and of viral antigens in fish leucocytes, respectively, using polymerase chain reaction (PCR) and flow cytometry (FC).

Animals↗
PubMed2001

First-derivative spectrophotometric and LC determination of nifedipine in Brij 96 based oil/water/oil multiple microemulsions on stability studies.

A first-derivative spectrophotometric (1D(387)) method was developed for the determination of nifedipine in oil/water/oil (O/W/O) multiple microemulsions during stability studies. The UV first-derivative spectra were recorded over the wavelength range 200-600 nm (Delta lambda=16). The derivative procedure was based on the linear relationship between nifedipine concentration and the first-derivative amplitude at 387 nm. This method was validated and compared with a liquid chromatography (LC) procedure used for the quantitative analysis of the drug. Both methods showed excellent precision and accuracy with values of 2.09 and 1.82%, respectively, for the LC method and of 1.53 and 1.64%, respectively, for the 1D(387) method. The established linearity range was 5-30 microg ml(-1) with r(2) values of 0.9980 and 0.9988 for LC and first-derivative procedures, respectively. Nifedipine recoveries from spiked placebos were >95% for both methods over the linear range analysed. These methods have been successfully used for determining of nifedipine content of multiple microemulsions during stability studies, since there was no interference with its decomposition products.

Calcium Channel Blockers↗
PubMed2001

Gene delivery from the E3 region of replicating human adenovirus: evaluation of the 6.7 K/gp19 K region.

The use of genetically engineered, replication-selective viruses to treat cancer is being realized with viruses such as ONYX-015, a human adenovirus that selectively destroys p53 mutant cancer cells. To enhance further the clinical efficacy of ONYX-015 and viruses like it, we have developed a novel gene delivery system for replicating adenoviruses. This system has two unique features. First, it uses the endogenous adenoviral gene expression machinery (promoter, splicing, polyadenylation) to drive transgene expression. Second, a single region or gene in the multi-gene E3 transcription unit is selectively substituted for by the therapeutic transgene(s). Analyzing various transgene substitutions for the 6.7 K/gp19 K region of E3, we demonstrate the following: (1) transgene expression in this system is predictable and mimics the substituted endogenous gene expression pattern, (2) expression of surrounding E3 genes can be retained, (3) the insertion site choice can effect both the transgene expression level and the viral life cycle, and, (4) expression levels from this system are superior to those generated from a replication-defective virus using the HCMV enhancer-promoter and this is dependent on viral DNA replication. This unique methodology has broad application to the rapidly evolving field of replicating virus-based therapies.

Adenovirus E3 Proteins↗
PubMed2001

Lipid and protein composition at different developmental stages of Pediculus capitis (Arthropoda, Phthiraptera).

Protein and lipid compositions were studied at different developmental stages of Pediculus capitis De Geer 1778. Phosphatidylcholine was found to be the predominant lipid at all stages and in both sexes. Palmitic and oleic acids were the main fatty acids throughout the 3 stages studied. A marked decline was observed in the total lipid content and triacylglyceride concentration during development, suggesting that their consumption is an energy source. The electrophoretic mobility revealed the predominance of a 320-kDa protein in eggs and adult females, whereas 2 major proteins of 514 and 439 kDa were found in nymphs, as well as in male and female adults. Two very high density lipoprotein fractions were isolated by ultracentrifugation of egg cytosol in a density gradient of NaBr. Both reserve lipoproteins contained phospholipids and triacylglycerols as the predominant lipids and a protein band of around 320 kDa. The structure of this band is likely to be similar to that found in females in a vitellogenic state.

Animals↗
PubMed2001

Clinical experience with HLA-B7 plasmid DNA/lipid complex in advanced squamous cell carcinoma of the head and neck.

OBJECTIVE: To investigate the safety and efficacy of alloantigen plasmid DNA therapy in patients with advanced head and neck squamous cell carcinoma using Allovectin-7 (Vical Inc, San Diego, Calif), a DNA/lipid complex designed to express the class I major histocompatibility complex antigen HLA-B7. DESIGN: Multi-institutional prospective trial. SETTING: Academic medical setting. PATIENTS: A total of 69 patients were enrolled in 3 sequential clinical trials: a single-center phase 1 trial and 2 multicenter phase 2 trials. Eligibility criteria included unresectable squamous cell carcinoma that failed conventional therapy, Karnofsky performance status score of 70 or greater, and no concurrent anticancer or immunosuppressive therapies. INTERVENTION: Patients received 2 biweekly intratumoral injections of 10 microg (phase 1 and first phase 2 trials) or 100 microg (second phase 2 trial) of Allovectin-7 followed by 4 weeks of observation. Patients with stable or responding disease after the observation period were given a second treatment cycle identical to the first. MAIN OUTCOME MEASURES: Patients were assessed for toxic effects, and tumor size was measured after cycles 1 (at 6 weeks) and 2 (at 16 weeks). RESULTS: Allovectin-7 treatment was well tolerated, with no grade 3 or 4 drug-related toxic effects. Of 69 patients treated, 23 (33%) had stable disease or a partial response after the first cycle of treatment and proceeded to the second cycle. After the second cycle, 6 patients had stable disease, 4 had a partial response, and 1 had a complete response. Responses persisted for 21 to 106 weeks. CONCLUSIONS: Intratumoral plasmid DNA immunotherapy for head and neck cancer with Allovectin-7 is safe, and further investigations are planned in patients with less advanced disease, where it could potentially improve patient survival and reduce the need for radical high-morbidity treatments.

Adult↗
PubMed2000

Comparison of UV spectrophotometric and LC methods for the determination of nortriptyline hydrochloride in polysorbate 80 based oil/water (o/w) microemulsions.

A new rapid, reliable and specific UV spectrophotometric method was developed for the determination of nortriptyline hydrochloride formulated into o/w microemulsions. The UV spectra of nortriptyline standard solution in methanol and placebo (microemulsion without nortriptyline) were recorded over the wavelength range 200-600 nm and the spectra for placebo and nortriptyline loaded microemulsion were recorded over the range 260-400 nm in order to determine the overlapping that might appears, and hence to set the wavelength that could be used for the quantitative analysis. This method was validated and compared with a liquid chromatography (LC) procedure used for the quantitative analysis of the drug. Both methods showed excellent precision and accuracy with RSD values of 2.37 and 1.41%, respectively, for the LC method, and values of 1.24 and 2.88%, respectively, for the UV spectrophotometric method. The established linearity range was 10-50 microg ml(-1) (r2 = 0.9985) and 20-60 microg ml(-1) (r2 = 0.9979) for the HPLC and UV spectrophotometric methods respectively. The recoveries of nortriptyline from spiked placebos were > 95% for both methods over the linear range. The methods have been successfully used for determining the nortriptyline content of microemulsions and for evaluating the chemical stability of the drug in nortriptyline-loaded microemulsions.

Antidepressive Agents, Tricyclic↗
PubMed2000

Release of nortriptyline hydrochloride from oil-water microemulsions.

The release of nortritptyline hydrochloride from oil-in-water (o/w) microemulsions (isopropyl myristate as oil, propylene glycol as cosurfactant, polysorbate 80 as surfactant and phosphate buffer, pH 7.4, as the continuous phase) containing increasing concentrations of polyethylene glycol 400, used to facilitate the diffusion of a drug from the inner oily phase of the microemulsion to the outer aqueous phase of such a dispersion system, was studied by determining the permeability constants of the drug through hydrophilic and lipophilic membranes separating the o/w microemulsions from the receiving aqueous phase (phosphate buffer pH 7.4). The permeability of nortriptyline hydrochloride from microemulsions through the lipophilic membrane increased as the concentration of polyethylene glycol 400 in the disperse system increased. The apparent permeability constant for nortriptyline hydrochloride, from the microemulsion without polyethylene glycol, was 1.36 x 10(-3) cm x h(-1), it increased up to 7.80 x 10(-3) cm x h(-1) in the presence of polyethylene glycol at a concentration of 50% (v/v) of the initial volume of the aqueous phase.

Adrenergic Uptake Inhibitors↗
PubMed2000

Psychological adjustment in a french cohort of type 1 diabetic children. PEDIAB Collaborative Group.

The aim of the study was to determine whether IDDM affects the course of psychological adjustment in youths. The study sample included 164 children with IDDM (mean age=10.2) and their parents compared to 164 healthy controls matched for age, sex and socioeconomic status. Adjustment was measured with the Child Behavior Checklist, a parental rating scale, validated and adapted for the French population. Two-way ANOVAs on CBCL scale scores showed that scores for both internalizing and externalizing problem behaviors and the total CBCL score were significantly raised in diabetic children (p<0.001). Further comparisons on the 8 narrow-band scale scores of the CBCL indicated increased scores for diabetic children on 6 dimensions. A significant Gender x Status (IDDM versus Controls) interaction was found, supportive of higher rates of aggressive behaviors amongst male diabetic children (p<0.01). Controlling for age, no correlation was found between CBCL total, internalizing and externalizing scores and duration of IDDM or HbA1c levels within the diabetic group. Psychological adjustment to chronic illness needs to be considered with respect to both normal developmental demands as well as in the context of the specific challenges posed by the disease.

Adolescent↗
PubMed2000

Lectures.

Explore the source record for details and available documents.

Journal Article↗
PubMed1999

Virus susceptibility of the fish cell line SAF-1 derived from gilt-head seabream.

The recently reported SAF-1 cell line from fins of gilt-head seabream was evaluated for susceptibility to lymphocystis disease virus (LDV) and to several salmonid fish viruses, such as infectious haematopoietic necrosis virus (IHNV), viral haemorrhagic septicemia virus (VHSV) and several strains of infectious pancreatic necrosis virus (IPNV). LDV, VHSV and IHNV replicated well in the cultured fin cells as demonstrated by cell lysis and increases in viral titer. The potential use of this cell line to detect viruses from fish marine species is discussed.

Animals↗
PubMed1999

Comparison of derivative spectrophotometric and liquid chromatographic methods for the determination of omeprazole in aqueous solutions during stability studies.

A first derivative spectrophotometric method was developed for the determination of omeprazole in aqueous solutions during stability studies. The derivative procedure was based on the linear relationship between the omeprazole concentration and the first derivative amplitude at 313 nm. The first derivative spectra was developed between 200 and 400 nm (deltalambda = 8). This method was validated and compared with the official high-performance liquid chromatography (HPLC) method of the USP. It showed good linearity in the range of concentrations studied (10-30 microg ml(-1)), precision (repeatability and inter-day reproducibility), recovery and specificity in stability studies. It also seemed to be 2.59 times more sensitive than the HPLC method. These results allowed to consider this procedure as useful for the rapid analysis of omeprazole in stability studies since there was no interference with its decomposition products.

Anti-Ulcer Agents↗
PubMed1999

Mechanisms of resistance to ampicillin, chloramphenicol and quinolones in multiresistant Salmonella typhimurium strains isolated from fish.

Mechanisms of antibiotic resistance and epidemiological relationships were investigated for five multiresistant strains of Salmonella typhimurium isolated from fish in India. Four strains showed resistance to nalidixic acid, chloramphenicol, tetracycline, co-trimoxazole, gentamicin and beta-lactam antibiotics. The remaining strain was susceptible to all beta-lactam antibiotics tested and to co-trimoxazole but resistant to the other antibiotics tested. Epidemiological analysis performed by REP-PCR showed that the five isolates belonged to the same clone. Resistance to nalidixic acid was related to a single mutation in the gyrA gene. Chloramphenicol resistance was related to the production of chloramphenicol acetyl-transferase. An OXA-1 beta-lactamase, located in an integron, was responsible for resistance to ampicillin. These results indicate the health hazard posed by the fact that S. typhimurium may acquire or develop several mechanisms of resistance to a variety of antibiotics, including quinolones, and can thus cause disease in humans which may be difficult to treat.

Ampicillin↗
PubMed1998

Characterization and Infectivity of Four Bacterial Strains Isolated from Brown Ring Disease-Affected Clams

Four bacterial strains isolated from carpet-shell clams (Ruditapes decussatus) and manila clams (R. philippinarum) exhibiting Brown Ring Disease (BRD) symptoms in Galicia (Northwest of Spain) were characterized using biochemical and serological techniques. Moreover their pathogenicity for clams and resistance against clam hemolymph were determined. All of the Vibrio isolates exhibited biochemical characteristics typical of the genus. Strains GR1703RP and GR6301RP, isolated from R. philippinarum showing signs of BRD, shared phenotypical and antigenic characteristics and bacterial extracellular products enzymatic activities with the Vibrio tapetis. Strains GR0705RD and GR0202RD, isolated from R. decussatus showing BRD signs, although biochemically similar to V. tapetis, did not show positive agglutination with V. tapetis antiserum. The virulence of the bacteria varied depending on the bacterial strain and clam species assayed. Mortalities were recorded for a 30-day period, reaching values ranging from 6 to 80%. Strain GR0202RD was the most virulent for R. philippinarum with a cumulative mortality rate of 45%, while the strain GR0705RD induced the highest prevalence of BRD signs, affecting 75% of the survivors. In the case of R. decussatus, the four bacterial strains produced a cumulative mortality rate higher than 45%. In general, bacterial strains, showed resistance to clams hemolymph. Copyright 1998 Academic Press. Copyright 1998 Academic Press

Journal Article↗
PubMed1998

Enteral nutrition by percutaneous endoscopic gastrojejunostomy in severe hyperemesis gravidarum: a report of two cases.

We describe the first two cases in which percutaneous endoscopic gastrojejunostomy was used as a means to provide enteral nutrition in severe hypermesis gravidarum. The use of this method of enteral access provided an alternative to parenteral nutrition, was well tolerated, cost-effective and had no major complications. In both cases the nutritional goal for mothers as well as appropriate fetal growth and development were achieved.

Adult↗