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Biomedical subjects

J M Carrasco

Publications and source records attributed to J M Carrasco.

17 recordsLinked to original sources

Organochlorinated pesticides in sediments from the Lake Albufera of Valencia (Spain).

Bottom sediment samples from 121 sites of the Lake Albufera of Valencia were analyzed. Dieldrin, endrin, heptachlor and op'-DDT were not detected (<0.01 ng g(-1)) in 88-93% of the sites. Aldrin and HCB concentration ranges were between <0.01 and 0.1 ng g(-1) in 86% and 94% of the sites, respectively. Heptachlor-epoxide and lindane 95% confidence intervals were 0.2-0.5 and 0.06-0.12, respectively. The greatest average concentration corresponds to pp'-DDE, pp'-DDD and pp'-DDT. The sum of six isomers and derivatives of the DDT average concentration reaches 2.1 ng g(-1), as opposed to 2.7 ng g(-1) for the sum of 13 pesticides considered. In the site with a major contamination, 27.0 ng g(-1) of pp'-DDD and 12.8 ng g(-1) of pp'-DDT were accumulated. The DDE:DDT proportion average was 0.37, indicating an aged DDT contamination. Concentrations of pesticides in sediments were compared to three sediment quality guidelines, and indicated that a low biological effects level can be expected in either sediments or aquatic organisms.

DDT↗

Acute health problems among subjects involved in the cleanup operation following the Prestige oil spill in Asturias and Cantabria (Spain).

The purpose of this study was to evaluate exposure conditions and acute health effects in subjects participating in the Prestige oil spill cleanup activities and the association between these and the nature of the work and use of protection devices in the regions of Asturias and Cantabria (Spain). The sample comprised 400 subjects in each region, selected from a random sampling of all persons involved in cleanup activities, stratified by type of worker and number of working days. Data were obtained via a structured questionnaire and included information on specific tasks, number of working days, use of protective materials, and acute health effects. These effects were classified into two broad groups: injuries and toxic effects. Data analysis was performed using complex survey methods. Significant differences between groups were evaluated using Pearson's chi(2) test. Unconditional logistic regression was used to compute odds ratios and 95% confidence intervals. Bird cleaners accounted for the highest prevalence of injuries (19% presented with lesions). Working more than 20 days in highly polluted areas was associated with increased risk of injury in all workers. Occurrence of toxic effects was higher among seamen, possibly due to higher exposure to fuel oil and its components. Toxic effects were more frequent among those working longer than 20 days in highly polluted areas, performing three or more different cleaning activities, having skin contact with fuel oil on head/neck or upper limbs, and eating while in contact with fuel or perceiving disturbing odors. No severe disorders were identified among individuals who performed these tasks. However, potential health impact should be considered when organizing cleanup activities in similar environmental disasters.

Accidents↗

Effects of propanil, tebufenozide and mefenacet on growth of four freshwater species of phytoplankton: a microplate bioassay.

The Albufera Natural Park situated in Valencia (Spain), with a very rich flora and fauna is surrounded by rice fields in which pesticide spraying is a regular practice. With this in mind, the sensitivity of four algal species, Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris and Chlorella saccharophila to pesticides propanil, tebufenozide and mefenacet was studied using single species toxicity tests. Organisms were exposed to different concentrations of these herbicides and the algal growth was measured in a microplate reader at 410 nm, at 0, 24, 48 and 72 h. Tebufenozide appeared to be the most inhibitory to Scenedesmus and Chlorella species growth. 72 h EC50 of propanil, tebufenozide and mefenacet ranged from 0.29 to 5.98 mg/l, 0.12 to 0.15 mg/l and from 0.25 to 0.67 mg/l, respectively for the four algal species. The two species of Chlorella were more tolerant than the two species of Scenedesmus.

Acetamides↗

Effects of the organophosphorus insecticide fenitrothion on growth in five freshwater species of phytoplankton.

The acute toxicity of the insecticide fenitrothion was measured using four freshwater algae (Chlorella saccharophila, Chlorella vulgaris, Scenedesmus acutus, and Scenedesmus subspicatus) and one cyanobacteria (Pseudanabaena galeata). Insecticide concentrations eliciting 50% growth reduction over 96 hr (EC50) ranged from 0.84 to 11.9 mg/L. Fenitrothion was more toxic than other pesticides studied with the same algal species such as chlorsulfuron, molinate, and pyridaphenthion. The transformation of effective concentrations of fenitrothion and other pesticides obtained from toxicity measurements into percent of the saturation level in water is used as a first evaluation of potential hazard to aquatic systems. The insecticides fenitrothion and pyridaphenthion were less hazardous than the herbicides atrazine, benthiocarb, cinosulfuron, chlorsulfuron, methyl-bensulfuron, and molinate. The two species of Chlorella and the cyanobacterium Pseudanabaena were more tolerant to fenitrothion than the two species of Scenedesmus.

Dose-Response Relationship, Drug↗

Bioconcentration of the insecticide pyridaphenthion by the green algae Chlorella saccharophila.

A study was undertaken to examine the uptake of the organophosphate insecticide pyridaphenthion in the chlorophyta Chlorella saccharophila. Algae cultures were exposed to the initial nominal concentration 10.0 mg l(-1) pyridaphention during seven days. The insecticide bioconcentrates in the biomass to the highest level of 441.5 +/- 25.9 mg kg(-1) on the fifth day of exposure and was followed by a decrease to 76.6 +/- 5.1 mg kg(-1) on the seventh day. A model was constructed to describe the dynamic process, which estimated a bioconcentration factor (BCF) equal to 28. The study demonstrates the potential of accumulation of pyridaphenthion in aquatic organisms and helps to expand the pyridaphenthion toxicity database. The replacement of fenitrothion by pyridaphenthion concerning their use in rice flooded cultures is discussed.

Absorption↗

Effects of pyridaphenthion on growth of five freshwater species of phytoplankton. A laboratory study.

The acute toxicity of the insecticide and acaricide pyridaphenthion to five species of freshwater phytoplankton, Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris, Chlorella saccharophila and Pseudanabaena galeata was determined. Insecticide concentrations eliciting a 50% growth reduction over 96 h (EC50) ranged from 2.2 to 30.9 mg/l. The two species of Chlorella and the cyanobacteria P. galeata were more tolerant than the two species of Scenedesmus. Concentrations of pyridaphenthion detected in some natural waters were less than the toxic threshold for these species.

Dose-Response Relationship, Drug↗

Detection of fusarin C and trichothecenes in Fusarium strains from Spain.

A group of 49 strains of Fusarium sp. isolated from different Spanish samples of cereals and mixed feedstuffs were screened for their ability to produce trichothecenes like T-2 toxin (T-2), HT-2 toxin (HT-2), diacetoxyscirpenol (DAS) and deoxynivalenol (DN), as well as other mycotoxin produced by Fusarium named fusarin C. The production of these mycotoxins was analyzed by means of spectrophotometry, thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and gas chromatography (GC). Results showed that from 19 Fusarium strains in which cultures trichothecene production was detected, 15 were HT-2 producers, 9 T-2 producers, 14 DAS producers and 10 DN producers. On the other hand, from 28 Fusarium strains in which cultures fusarin C production was detected, 22 were low fusarin C producers (ranged from 0.04 to 1 microgram/l ICI medium), 5 Fusarium strains were intermediate-level producers (ranged from 1 to 10 micrograms/l ICI medium) and one Fusarium strain produced 240 micrograms/l ICI medium. The identified Fusarium strains that produced trichothecenes and fusarin C were F. moniliforme and F. oxysporum.

Chromatography, Gas↗

[Effect of the prolonged use of intrauterine devices and oral contraceptive on iron nutrition].

The aim of this work was to study the effect of prolonged use of intrauterine devices (IUD) and oral contraceptives (OCO) normally prescribed at outpatient clinics of the Health Service on iron nutrition. Two hundred twenty three healthy women, aged 20 to 39 years were studied. Of these, 100 were using IUD and 97 OCO for three to five years and 26 were not using any pharmacological or mechanical contraceptive method (control group). Serum ferritin was significantly higher in the OCO group compared to IUD and control groups (58.9 +/- 2.2; 26.2 +/- 2.1 and 21.1 +/- 2.4 ng/ml respectively). There was a positive correlation between serum ferritin and hemoglobin in IUD and control groups and between ferritin and transferrin saturation in the OCO and control groups. The frequency of storage iron depletion (defined as a serum ferritin < 12 ng/ml) was 6.3, 0 and 25% in the IUD, OCO and control groups respectively. The numbers for iron-deficient erythropoiesis (defined as a transferrin saturation < 15%) were 7, 3 and 4% and for iron deficiency anemia, 6.5, 0 and 8%. It is concluded that the chronic use of IUDs leads to iron depletion and that measures to improve iron nutrition among women using them should be adopted.

Adult↗

Molinate decontamination processes in effluent water from rice fields.

The performance of aeration, photodecomposition and biological degradation processes as methods to reduce molinate contamination levels in effluent water from rice fields was studied. Aeration produced a molinate dissipation of 84%, as against 22% without aeration. Application of UV-light to clean water solutions achieved a molinate photodecomposition of 96% in 24 h. Maximal degradation obtained in algal cultures was 55% in 20 days and 78% in 40 days. In micro-organism cultures, kept in darkness and with a continuous flow of aqueous solution of molinate and inorganic salts, a degradation of 97% was achieved.

Azepines↗

Pesticide residues in total diet samples, Spain--1971-72.

Average pesticide residue levels were determined for the 17 main food groups in the average Spanish diet. Using these levels and the estimated average intake of these foods, authors computed an individual's average daily consumption of pesticides from each of these food groups and her/his total diet. Foods were acquired over a 1-year period from the market of Valencia, a city that gets supplies from an agricultural area where pesticide consumption is appreciably higher than that of the rest of the country. Thus average residue levels found must be higher than the national average. Except for fruits and vegetables, the different items composing each food group were sampled in proportion to the amount consumed in the average Spanish diet. Foods forming each group were homogenized into composite samples. All foods were analyzed raw. The most frequently detected pesticides were DDT and BHC. Malathion was detected at levels less than 0.10 ppm in some samples of vegetable oils, pears, and apples. DDT and BHC levels varied from undetectable to amounts less than 1.0 ppm. Highest levels were found in lard. An individual's average daily intake of pesticides was calculated to be 78 mug DDT, a sum which includes residues of o,p'-DDT, p,p'-DDT, and p,p'-DDE, and 13.8 mug gamma-BHC. These levels are much lower than the maximum acceptable daily limits established by the United Nations Food Agricultural Organization and World Health Organization.

Chromatography, Gas↗

[Lipid vehicles for the parenteral administration of drugs (1): emulsions].

To increase the efficiency of medication used in therapy and diagnostics, there have been, during the last decades, important advances in the inclusion techniques hereof, in vehicles which give greater selectivity and tolerance. Among the colloidal vehicle systems of medications with different medications, the object of the present review study. Therefore, we analyze the rationale of their use as a vehicle of medication, their physical and chemical characteristics, the ways of elimination after their administration, as well as the formulations in oil-water emulsions for the parenteral administration of diferent active substances such as diazepam, propofol, methohexital, ethomidate, amphotericin B, cytostatics, and cyclosporine, among others. The results of published studies on the efficiency and therapeutic applications of these are presented.

Amphotericin B↗