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Biomedical subjects

A Otero

Publications and source records attributed to A Otero.

At least 55 records · Page 3Linked to original sources
PubMed2001

Two-stage cultures for the production of astaxanthin from Haematococcus pluvialis.

A two-stage culture system was established for the production of astaxanthin from Haematococcus pluvialis. In a first stage green vegetative cells were produced in semicontinuous cultures maintained with daily renewal rates between 10 and 40%. The steady-state cell density decreased with increasing renewal rates. Highest cell productivity, 64 x 10(6) cells l(-1) day(-1) was obtained with a daily renewal rate of 20%. In a second stage the harvested cultures were submitted to high light (240 micromol photon m(-2) s(-1)) under batch conditions for 15 days in order to stimulate the transition to the aplanospore stage and the accumulation of astaxanthin. No decrease in cell density was recorded during the induction period in any of the cultures. Cultures obtained at high renewal rates continued growing during the induction period and no astaxanthin was accumulated until all nitrogen in the media had been consumed. The final concentration of astaxanthin was inversely correlated to the growth rate at which first-stage cultures were maintained. Optimal renewal rate for maximal astaxanthin production depended on the duration of the induction period. After a 12-day induction period the highest astaxanthin production, 5.8 mg l(-1) of semi-continuous culture day -1, was obtained with cultures maintained at a renewal rate of 20%. When the induction period was increased to 15 days maximal astaxanthin productivity, 9.6 mg l(-1) of semi-continuous culture day -1, was obtained from cultures maintained at a renewal rate of 40% despite the much lower astaxanthin concentration achieved in these cultures. Results demonstrate the feasibility of semi-continuous cultivation of H. pluvialis for the two-stage production of astaxanthin.

Chlorophyta↗
PubMed2001

Relationship between atmospheric pressure and mortality in the Madrid Autonomous Region: a time-series study.

This study set out to determine the possible influence of variations in atmospheric pressure on mortality in the Madrid Autonomous Region (MAR), taking into account the possible confounding effect of other atmospheric variables. The study was based on daily mortality data from the MAR Revenue and Excise Authority, meteorological data from Getafe Observatory and air pollution data from the Madrid Municipal Automatic Air Pollution Monitoring Grid. A time-series analysis was performed, using Box-Jenkins modelling and controlling for the respective confounding variables. Furthermore, the different variables studied (pressure, temperature, pollutants, etc.) were used to produce a multivariate model of the different causes of mortality. A significant association was found between anticyclonic trend and mortality with circulatory causes in the medium-long term and anticyclonic trend and mortality with respiratory causes in the long term.

Air Pollution↗
PubMed2001

Growth Rate of the microalga Tetraselmis suecica changes the biochemical composition of Artemia species.

The impact of different microalgal semicontinuous cultures on growth and biochemical composition in the next link of the food chain was tested using the filter feeder Artemia species as a model. The marine microalga Tetraselmis suecica was cultured semicontinuously with renewal rates between 10% and 50% and used to feed Artemia. Microalgal cultures maintained with a low renewal rate that had biochemical composition similar to that of the stationary-phase cultures commonly used in aquaculture produced poor growth and survival and low food-conversion efficiency compared to cultures maintained with a high renewal rate. Changes in the renewal rate in microalgal cultures also resulted in important changes in the gross biochemical composition of the filter feeder. The gross biochemical composition of the Artemia resembled that of the microalgae used as food except for total lipid content. The percentage of protein in the organic fraction of Artemia increased from 45% to 65% of the organic weight with increasing renewal rates in the microalgal cultures, while the carbohydrate percentage decreased under the same conditions. Higher renewal rates resulted in higher lipid percentages in the microalga, but in Artemia the percentage of lipids decreased from 19% of the organic weight with a renewal rate of 10%, to 13% with a renewal rate of 50%. The percentage of all polyunsaturated fatty acids in Artemia, including 20:5n-3, increased slightly with increasing renewal rates in the microalgal cultures. Results emphasize the importance of controlling microalgal nutritional value for the success of aquaculture food chains in which filter feeders are involved.

Journal Article↗
PubMed2001

Subtyping of panic disorder patients with bradycardia.

PURPOSE: Since clinical practice suggests that panic disorder may not be a homogeneous condition, a study was carried out to test the possible existence of different groups or subgroups of panic patients. SUBJECTS AND METHODS: Thirty-two panic patients (DSM-III-R) underwent lactate challenge in our laboratory and were assessed for heart rate, blood pressure, sweating and Acute Panic Inventory. RESULTS: During the lactate challenge, patients complaining mainly of 'cardiorespiratory' symptoms (N = 12) showed tachycardia and localized sweating. Conversely, patients complaining mainly of 'pseudoneurological' symptoms (N = 16) showed bradycardia and generalized sweating. In both groups, Acute Panic Inventory scores were significantly higher during than before the panic attack, but the distribution of the scores was markedly different. DISCUSSION AND CONCLUSION: The results suggest that panic disorder may be a heterogeneous condition. Implications of these results to other phobic disorders, to Klein's false suffocation alarm theory and to the 'extended amygdala model' are discussed.

Acute Disease↗
PubMed2001

Development of a monoclonal antibody specific to a recombinant envelope protein from dengue virus type 4 expressed in Pichia pastoris.

A mouse monoclonal antibody (MAb, 4B6) was able to recognize dengue virus type 4 envelope (E) protein both as a recombinant protein in Pichia pastoris and when it was present in infected brains of suckling mice. 4B6 was characterized by enzyme-linked immunoadsorbent assay (ELISA), hemaglutination inhibition, neutralization, and immunoblot. The MAb was isotyped as IgG2a. It was serotype 4 specific and it inhibited hemaglutination and neutralized homologous virus. It did not enhance infection of P338D1 cells by dengue type 4 virus strain H-241 strain. This MAb was reactive with recombinant E protein and dengue 4 virus, as revealed by Western blot. In vivo, MAb 4B6 conferred passive protection in mice challenged with homologous virus. Currently, this MAb is being used to purify recombinant E protein for further studies.

Animals↗
PubMed2001

Support from children, living arrangements, self-rated health and depressive symptoms of older people in Spain.

OBJECTIVE: To assess the association between emotional and instrumental support from children and living arrangements with the physical and mental health of older people in Spain. METHODS: A face-to-face home interview was carried out with 1284 community-dwelling people over 65 (response rate = 83%) randomly sampled according to an age- and sex-stratified sampling scheme in 1993 at Leganés (Spain). Close to 93% of the participants had children and 45% of them coresided with them. Depressive symptoms were assessed by the CES-D (Center for Epidemiologic study depression scale) and self-rated health (SRH) by a single-item question. Emotional support was measured with a six-item scale on affection and reciprocity. Instrumental support was assessed by help received from children in 17 activities of daily living. Four living arrangements were considered: Living with spouse only, living with a spouse and children, widower living alone, and widower living with children. RESULTS: Multivariate analysis controlling for age, gender, education and functional status showed that low emotional support and reception of instrumental aid were significantly associated with poor SRH. Being a widower and sharing living arrangements with children was associated with good SRH. Living arrangements modify some of the associations of support of children with SRH. Depressive symptoms were associated with low emotional support, reception of instrumental help and being a widower who did not share living arrangements with children. For widowers who do not cohabit with children, reception of instrumental aid is associated with low depressive symptomatology. DISCUSSION: Emotional support from children seems to play an important role in maintaining the physical and mental health of elderly people in Spain. Instrumental support is widely available. Coresidence with children is very common and it is associated with good self-perceived health and low prevalence of depressive symptoms in a culture where family interdependence is highly valued. Families should be protected and encouraged to continue care-giving through a variety of community services and respite care, adapted to their needs and preferences. Research should be undertaken to find more efficient ways to help family caregivers in the Mediterranean context.

Activities of Daily Living↗
PubMed2001

[Estimating the supply of medical specialists in Colombia by using the capture-recapture method].

OBJECTIVE: Given that it is not known how many medical doctors there are in Colombia and that, without that datum, studies of demand are simply theoretical exercises, we proposed to estimate the supply of 12 medical specialties in Colombia, using the capture-recapture technique, which was developed by zoologists to estimate wild-animal populations. METHODS: Three lists, or "captures," were used: 1) university degrees obtained abroad and graduates of postgraduate programs in Colombia, 2) members of medical societies, and 3) specialists in the principal health care enterprises. To estimate the total population we used the CAPTURE software program. RESULTS: A total of 24,910 records were obtained: 8,397 from the university records, 6,561 from the scientific societies, and 9,952 from the health care businesses. More than half of the physicians have entered the labor market during the last decade. The estimated number of physicians (with the 95% confidence interval) for each specialty was: anesthesiology, 1,753 (1,727 to 1,789); cardiology, 607 (598 to 624); dermatology, 517 (514 to 525); obstetrics and gynecology, 2,338 (2,290 to 2,400); pulmonary disease, 304 (297 to 320); neurosurgery, 324 (319 to 334); neurology, 321 (296 to 369); ophthalmology, 1,049 (1,042 to 1,061); orthopedics, 1,217 (1,212 to 1,227); otolaryngology, 634 (628 to 645); psychiatry, 855 (838 to 879); and urology, 452 (452 to 458). CONCLUSIONS: The capture-recapture technique is useful in the study of human resources. In Colombia the number of specialists doubled in less than a decade. There are specialties that are already oversupplied, such as neurosurgery. All the other specialties show growth rates that indicate a future over-supply for the health care system.

Colombia↗
PubMed2001

Mesophilic aeromonads in wild and aquacultured freshwater fish.

Numbers and species of motile Aeromonas were determined in freshly caught freshwater fish, in the surrounding environment, and also during iced chilled storage of fish specimens. Although no significant differences were observed in water samples, initial levels for skin, gill, and intestines were significantly lower in farmed rainbow trout (Oncorhynchus mykiss) than in wild brown trout (Salmo trutta) and pike (Esox lucius). During storage of wild specimens, naturally occurring aeromonads grew fairly well on the surfaces of skin and body cavity. Of 171 strains assigned to the genus Aeromonas, 88% were identified to phenospecies and putative genospecies level by using comprehensive biochemical schemes. The isolates were allocated to putative hybridization groups (HGs) 1 and 3 Aeromonas hydrophila (29%); putative HG 8 Aeromonas veronii biovar sobria (19%); putative HG 2 Aeromonas bestiarum (18%); putative HG 9 Aeromonas jandaei (16%); putative HGs 4 and 5a Aeromonas caviae (2%); putative HG 12 Aeromonas schubertii (2%); and putative HG 11 (unnamed, 0.6%). The remaining 20 isolates (12%) resembled A. schubertii but could not be allocated to currently recognized phenospecies or to putative HGs. Although cultured rainbow trout yielded strains of putative HGs 1, 4, and 8, which appear to be of major clinical importance, most isolates assigned to putative HGs 1 and 8 were recovered from pike. Differences among HGs found in wild animals could be related to their origin (unpolluted rivers for brown trout and urban rivers for pike). The recovery of these aeromonads species was not related to sampling site. The initial levels of motile aeromonads, their behavior during storage, and the strong potential spoilage activity of most isolates confirm that these bacteria can contribute to deterioration of iced wild freshwater fish. Although adequate cooking would inactivate motile aeromonads, the high incidence of isolates belonging to gastroenteritis-associated HGs should be regarded as a potential health concern, particularly for susceptible populations when there is a possibility of cross-contamination.

Aeromonas↗
PubMed2001

Bacteriological quality of aquacultured freshwater fish portions in prepackaged trays stored at 3 degrees C.

Fresh trout fillets and salmon slices packed in trays were obtained from two multinational chain supermarkets and evaluated for freshness and bacteriological quality immediately after packaging and during storage at 3 degrees C. Initial aerobic counts at 30 and 25 degrees C were significantly (P < 0.05) lower in trout fillets (5.27 +/- 0.57 and 4.87 +/- 0.80 log CFU/g, respectively) than in salmon slices, where levels in excess of 6 log CFU/g were found. In both products, initial Enterobacteriaceae counts were slightly higher than 3 log CFU/g and increased significantly during shelf life by approximately 3 log CFU/g. Most of the enterobacteria were identified as Citrobacter freundii, Hafnia alvei, and Enterobacter cloacae. On day 0, most probable number (MPN) counts of total and fecal coliforms were not significantly different, numbers of the latter group being approximately 4 MPN/g. Escherichia coli was only detected when fish was spoiled. Although initial presumptive Staphylococcus aureus counts were approximately 3 log CFU/g, only 4 of 84 selected colonies belonged to this species. Neither Salmonella nor antimicrobial residues were detected in any sample. Ethanol content in salmon slices did not significantly (P > 0.05) increase until they became inedible. Significant correlation (r = +0.72, P < 0.05) was observed between this chemical index and viable counts at 30 degrees C only when salmon slices were inedible. Trout fillets were acceptable for 7 days, and salmon slices showed signs of spoilage after 4 days. Although public health concerns associated with packed trout and salmon appear to be minimal, data on sensory quality, shelf life, and total viable and Enterobacteriaceae counts strongly suggest the need to improve the quality control systems used by European multinational retailers, especially for imported salmon.

Animals↗
PubMed2001

A model for forecasting emergency hospital admissions: effect of environmental variables.

This study modeled patterns and trends in emergency hospital admissions at a hospital in Madrid, Spain. The purpose was to quantify qualitative associations that have been detected between such admissions and a number of environmental variables. The following data were used: unscheduled daily emergency hospital admissions, Madrid air pollution data, and meteorological data. Time-series analysis was performed, with Box-Jenkins modeling. A multivariate model was constructed, incorporating the different causes of admissions and the respective environmental variables. Statistically significant associations were found between hospital admissions and other variables, indicating relationships with temperature, relative humidity, and mean daily tropospheric ozone concentrations. Whereas the effect of heat on admissions was short term, that of cold was in evidence from the second week. The association with ozone showed a seven-day lag and basically manifested itself as an influence on admissions for circulatory disease.

Cardiovascular Diseases↗
PubMed2000

Optimization of culture medium for the continuous cultivation of the microalga Haematococcus pluvialis.

The freshwater microalga Haematococcus pluvialis is one of the best microbial sources of the carotenoid astaxanthin, but this microalga shows low growth rates and low final cell densities when cultured with traditional media. A single-variable optimization strategy was applied to 18 components of the culture media in order to maximize the productivity of vegetative cells of H. pluvialis in semicontinuous culture. The steady-state cell density obtained with the optimized culture medium at a daily volume exchange of 20% was 3.77 x 10(5) cells ml(-1), three times higher than the cell density obtained with Bold basal medium and with the initial formulation. The formulation of the optimal Haematococcus medium (OHM) is (in g l(-1)) KNO3 0.41, Na2HPO4 0.03, MgSO4 x 7H2O 0.246, CaCl2 x 2H2O 0.11, (in mg l(-1)) Fe(III)citrate x H2O 2.62, CoCl2 x 6H2O 0.011, CuSO4 x 5H2O 0.012, Cr2O3 0.075, MnCl2 x 4H2O 0.98, Na2MoO4 x 2H2O 0.12, SeO2 0.005 and (in microg l(-1)]) biotin 25, thiamine 17.5 and B12 15. Vanadium, iodine, boron and zinc were demonstrated to be non-essential for the growth of H. pluvialis. Higher steady-state cell densities were obtained by a three-fold increase of all nutrient concentrations but a high nitrate concentration remained in the culture medium under such conditions. The high cell productivities obtained with the new optimized medium can serve as a basis for the development of a two-stage technology for the production of astaxanthin from H. pluvialis.

Chlorophyta↗
PubMed2000

Psychrobacters and related bacteria in freshwater fish.

Three phenotypic identification systems were employed to identify 106 strains of gram-negative, nonmotile, aerobic bacteria obtained during iced storage of wild (Salmo trutta and Esox lucius) and farmed (Oncorhynchus mykiss) freshwater fish. Using diagnostic tables and computer-assisted identification, the isolates were Psychrobacter (64 strains), Acinetobacter (24 strains), Moraxella (6 strains), Chryseobacterium (5 strains), Myroides odoratus (2 strains), Flavobacterium (1 strain), Empedobacter (1 strain), and unidentified (3 strains). Overall similarities of all strains were determined for 108 characters by numerical analysis (simple matching coefficient of similarity [S] and clustering by unweighted pair group average linkage [UPGMA]). At the 77% similarity level, 92 strains formed nine major clusters (3 or more strains) and four small clusters (2 strains). Cluster 1 (25 isolates divided into two main subclusters) could be assigned to Psychrobacter phenylpyruvicus, clusters 2 and 3 (26 isolates) were designated as Psychrobacter immobilis, and clusters 4 (3 isolates) and 7 (4 isolates) were identified as Psychrobacter urativorans and Psychrobacter spp., respectively. Clusters 5 (five isolates), 6 (three isolates), and 9 (five isolates) were labeled as Acinetobacter spp., Acinetobacter johnsonii, and Acinetobacter lwoffii, respectively. Cluster 8 (12 isolates), with a high resemblance to Thornley's phenon 4 (a heterogeneous group of bacteria isolated from poultry and related to Acinetobacter), remained unnamed. The restriction pattern was identical for strains grouped into clusters 2 and 3 (P. immobilis) but was different for the remaining Psychrobacter isolates. A large proportion of isolates belonging to the family Moraxellaceae were closely related. Psychrobacters and A. johnsonii were present in freshly caught fish and river water. In the latter stages of storage, P. phenylpyruvicus and acinetobacters tended to decrease, whereas P. immobilis increased.

Animals↗
PubMed1999

Behaviour of Listeria spp. in naturally contaminated chorizo (Spanish fermented sausage).

Counts of Listeria spp. were determined during the manufacture and drying of 21 lots of five chorizo varieties produced by three different manufacturers. Presumptive Listeria were not isolated from any of the batches produced in a large factory (F3) using starter, sorbate and controlled ripening at high temperatures. Initial levels in factory 1 (F1), with no starter added, but controlled ripening at low temperatures, were ca 3.5 log10 cfu/g while those in factory 2 (F2), with no starter added and ripening under natural climatic conditions, were 1.17 log10 cfu/g. Numbers of listeriae in batches obtained from F1 remained almost constant before decreasing by ca 0.5 log units/g in the finished product (32 days), while the levels in F2 increased by 1.47 log units/g after 11 days of ripening and declined further to levels above the original amount. Manufacturing procedure and smoking significantly affected presumptive listeriae counts. Thirteen strains recovered from F1 batches were identified as: Listeria monocytogenes (three strains of serovar 1/2c), Listeria innocua (eight strains of serovar 6b) and Listeria welshimeri (two strains of serovar 6b). Listeria strains from F2 were assigned to L. innocua and L. welshimeri.

Animals↗
PubMed1999

Modeling of air pollution and its relationship with mortality and morbidity in Madrid, Spain.

OBJECTIVE: Evaluation of the association between air pollution and mortality and morbidity is becoming ever more complex owing to changes in inner-city air pollution, marked by decreasing values for all main pollutants save those associated with traffic. This has led to the need for the study of new epidemiological scenarios in which most pollutants are below guideline values. Nonetheless, the health effects are significant. METHODS: This report presents the results of a statistically based model for real-time forecasting of mortality and morbidity in Madrid, with meteorological and pollution series serving as inputs. RESULTS AND CONCLUSIONS: Not only did the models perform well with correlation coefficients between predicted and observed values (r = 0.683 for mortality, r = 0.681 for morbidity), but they enabled quantification of the impact of air pollution on mortality and morbidity (with increases ranging from 1. 8% to 12% for mortality and from 2.3% to 18% for morbidity for a 25-microg/m(3) increase in pollutants). Moreover, attention should be drawn to the observation that the model proved to be easy to implement and operate on a routine basis.

Air Pollution↗
PubMed1999

In vitro inhibition of the replication of haemorrhagic septicaemia virus (VHSV) and African swine fever virus (ASFV) by extracts from marine microalgae.

We have screened for in vitro inhibition of viral replication with extracts from the following marine microalgae: Porphyridium cruentum, Phaeodactylum tricornutum, Tetraselmis suecica, Chlorella autotrophica, Dunaliella tertiolecta, Dunaliella bardawil, Isochrysis galbana, Isochrysis galbana var Tiso, Ellipsoidon sp. and Tetraselmis tetrathele. We have used as viral models two enveloped viruses of significant economic importance, the viral hemorrhagic septicemia virus (VHSV) of salmonid fish and the African swine fever virus (ASFV). The aqueous extracts from P. cruentum, C. autotrophica and Ellipsoidon sp., produced a significant inhibition of the in vitro replication of both viruses in a dose-dependent manner. That this inhibition could be due to sulfated polysaccharides was suggested because the same pattern of viral inhibition was obtained by using exocellular extracts from microalgae enriched in these compounds and/or dextran sulfate of high molecular weight. However, the inhibition of viral replication did not correlate with the percentage of sulfatation of the exocellular polysaccharides. Extracts from marine microalgae may have prophylactic utility against fish and mammalian viral diseases.

African Swine Fever Virus↗