Ecotoxicity of five veterinary antibiotics on indicator organisms and water and soil communities

This study explores the environmental effects of five common veterinary antibiotics widely detected in the environment, (chlortetracycline,CTC; oxytetracycline,OTC; florfenicol,FF; neomycin, NMC; and sulfadiazine, SDZ) on four bioindicators: Daphnia magna, Vibrio fischeri, Eisenia fetida, and Allium cepa, representing aquatic and soil environments. Additionally, microbial communities characterized through 16 S rRNA gene sequencing from a river and natural soil were exposed to the antibiotics to assess changes in population growth and metabolic profiles using Biolog EcoPlates™. Tetracyclines are harmful to Vibrio fisheri (LC50 ranges of 15-25 µg/mL), and the other three antibiotics seem to only affect D. magna, especially, SDZ. None of the antibiotics produced mortality in E. fetida at concentrations below 1000 mg/kg. NMC and CTC had the highest phytotoxicities in A. cepa (LC50 = 97-174 µg/mL, respectively). Antibiotics significantly reduced bacterial metabolism at 0.1-10 µg/mL. From the highest to the lowest toxicity on aquatic communities: OTC > FF > SDZ ≈ CTC > NMC and on edaphic communities: CTC ≈ OTC > FF > SDZ > NMC. In river communities, OTC and FF caused substantial decreases in bacterial metabolism at low concentrations (0.1 µg/mL), impacting carbohydrates, amino acids (OTC), and polymers (FF). At 10 µg/mL and above, OTC, CTC, and FF significantly decreased metabolizing all tested metabolites. In soil communities, a more pronounced decrease in metabolizing ability, detectable at 0.1 µg/mL, particularly affected amines/amides and carboxylic and ketonic acids (p < 0.05). These new ecotoxicity findings underscore that the concentrations of these antibiotics in the environment can significantly impact both aquatic and terrestrial ecosystems.

Hydroquinone Ecotoxicity: Unveiling Risks in Soil and River Ecosystems with Insights into Microbial Resilience

Despite widespread industrial use, the environmental safety of hydroquinone (HQ), a benzene compound from plants used in processes like cosmetics, remains uncertain. This study evaluated the ecotoxicological impact of HQ on soil and river environments, utilizing non-target indicator organisms from diverse trophic levels: Daphnia magna, Aliivibrio fischeri, Allium cepa, and Eisenia fetida. For a more environmentally realistic assessment, microbial communities from a river and untreated soil underwent 16S rRNA gene sequencing, with growth and changes in community-level physiological profiling assessed using Biolog EcoPlate™ assays. The water indicator D. magna exhibited the highest sensitivity to HQ (EC50 = 0.142 µg/mL), followed by A. fischeri (EC50 = 1.446 µg/mL), and A. cepa (LC50 = 7.631 µg/mL), while E. fetida showed the highest resistance (EC50 = 234 mg/Kg). Remarkably, microbial communities mitigated HQ impact in both aquatic and terrestrial environments. River microorganisms displayed minimal inhibition, except for a significant reduction in polymer metabolism at the highest concentration (100 µg/mL). Soil communities demonstrated resilience up to 100 µg/mL, beyond which there was a significant decrease in population growth and the capacity to metabolize carbohydrates and polymers. Despite microbial mitigation, HQ remains highly toxic to various trophic levels, emphasizing the necessity for environmental regulations.

Synergistic Activity of Thymol with Commercial Antibiotics against Critical and High WHO Priority Pathogenic Bacteria

The use of synergistic combinations between natural compounds and commercial antibiotics may be a good strategy to fight against microbial resistance, with fewer side effects on human, animal and environmental, health. The antimicrobial capacity of four compounds of plant origin (thymol and gallic, salicylic and gentisic acids) was analysed against 14 pathogenic bacteria. Thymol showed the best antimicrobial activity, with MICs ranging from 125 µg/mL (for Acinetobacter baumannii, Pasteurella aerogenes, and Salmonella typhimurium) to 250 µg/mL (for Bacillus subtilis, Klebsiella aerogenes, Klebsiella pneumoniae, Serratia marcescens, Staphylococcus aureus, and Streptococcus agalactiae). Combinations of thymol with eight widely used antibiotics were studied to identify combinations with synergistic effects. Thymol showed synergistic activity with chloramphenicol against A. baumannii (critical priority by the WHO), with streptomycin and gentamicin against Staphylococcus aureus (high priority by the WHO), and with streptomycin against Streptococcus agalactiae, decreasing the MICs of these antibiotics by 75% to 87.5%. The kinetics of these synergies indicated that thymol alone at the synergy concentration had almost no effect on the maximum achievable population density and very little effect on the growth rate. However, in combination with antibiotics at the same concentration, it completely inhibited growth, confirming its role in facilitating the action of the antibiotic. The time-kill curves indicated that all the combinations with synergistic effects were mainly bactericidal.

Optical Interrogation of Single Levitated Droplets in a Linear Quadrupole Trap by Cavity Ring-Down Spectroscopy

Optical trapping is a well-established technique to manipulate and levitate micro- and nanoscale particles and droplets. However, optical traps for single aerosol studies are most often limited to trapping spherical nonabsorbing droplets, and a universal optical trap for the stable confinement of particles regardless of their absorption strength and morphology is not established. Instead, new opportunities arise from levitating droplets using electrodynamic traps. Here, using a combined electrodynamic linear quadrupole trap and a cavity ring-down spectrometer, we demonstrate that it is possible to trap single droplets and simultaneously measure their extinction cross sections and elastic scattering phase functions over extended periods of time. To test the novel setup, we evaluated the evaporation of 1,2,6-hexanetriol under low-humidity conditions, and the evolution of aqueous (NH₄)₂SO₄ and NaCl droplets experiencing changing environmental conditions. Our studies extended beyond spherical droplets and we measured particle extinction cross sections after the efflorescence (crystallization) of the inorganic salt particles. Comparison of measured cross sections for crystallized particles with light scattering model predictions (using Mie theory or the T-matrix/extended boundary-condition method (EBCM) implementations for random orientation, with either the spheroid or superellipsoid parameterizations) enables information on particle shape to be inferred. Specifically, we find that cross sections for dry (NH₄)₂SO₄ particles are accounted for by Mie theory and, thus, particle shape is represented well by a sphere. Conversely, the cross sections for dry NaCl particles are only reconciled with light scattering models pertaining to nonspherical shapes. These results will have implications for accurate remote sensing retrievals of dry salt optical properties and for parameterizations implemented in radiative forcing calculations with changing humidity. Moreover, our new platform for precise and accurate measurement of optical properties of micron-scale and sub-micron particles has potential applications in a range of areas of atmospheric science, such as precise light scattering measurements for ice crystals and mineral dust. It represents a promising step toward accurate characterizations of optical properties for nonspherical and light-absorbing aerosols.

Testing a Paul trap through determining the evaporation rate of levitated single semi-volatile organic droplets

Rigorous knowledge of the optical fingerprint of droplets is imperative for the understanding of complex aerosol processes. Here, a Paul trap is operated to store single semi-volatile organic droplets in air. The droplets are illuminated with a green laser and the elastic scattering is collected on a CMOS camera. The setup provides excellent performance in terms of confinement and stability, allowing us to detect size changes of the order of few nanometres. The stability also allows us to measure vapour pressures with remarkable reproducibility. This approach supplies a robust method for the optical interrogation in the sub-micron range.

Full path single-shot imaging of femtosecond pulse collapse in air turbulence

In a single shot, we measure the full propagation path, including the evolution to pulse collapse, of a high power femtosecond laser pulse propagating in air. Our technique enables examination of the effect of parameters that fluctuate on a shot-to-shot basis, such as pulse energy, pulse duration, and air turbulence-induced refractive index perturbations. We find that even in lab air over relatively short propagation distances, turbulence plays a significant role in determining the location of pulse collapse.

A major fish stranding caused by a natural hypoxic event in a shallow bay of the eastern South Pacific Ocean

A massive beaching and mortality of fishes occurred in Coliumo Bay, a shallow bay located along the coast of the eastern South Pacific Ocean on 3 January 2008. This stranding was a consequence of an abrupt decrease in the dissolved oxygen concentration throughout the whole water column, due to the effect of intense upwelling along the coast off central-southern Chile. The main objectives of this study were: (1) to characterize taxonomically and biologically the fish species assemblage present in this beaching; (2) to evaluate several physiological indicators for the condition of the beached species at the time of their death; and (3) to assess the possible cause-effect mechanisms involved in the fishes death and the changes that took place in the fish community throughout the time. In this beaching, 26 fish species were identified: 23 teleosts, one myxiniform and two elasmobranchs. Most beached specimens were juveniles. Haematological and histological evidence indicate that severe hypoxia that lasted for at least 48 h was the most plausible cause of death. The main conclusion of this study is that the presence of oxygen-poor equatorial sub-surface water in the shallow coastal zone due to intense regional-scale upwelling caused the fish stranding. Although the effect of the hypoxic event was severe for the fish assemblage of Coliumo Bay, the rapid recuperation observed suggests that hypoxic events at the local spatial scale can be buffered by migration processes from the fish community inhabiting close by areas non-affected by low oxygen conditions. The effect that severe hypoxic events may have on larger spatial scales remains unknown.

Hemopoietic stem cell transplantation in refractory rheumatoid arthritis is not a contraindication for reconstructive surgery

Hemopoietic stem cell transplantation (HCST) is an experimental therapy that may produce prolonged remissions in patients with rheumatoid arthritis (RA) resistant to other treatments. Prosthetic articular replacement is often required in severe long-lasting disease. There is a well-founded concern regarding the feasibility and safety of reconstructive surgery after HSCT and as yet no published data on the subject. We report a patient with RA of 9 years' duration resistant to conventional treatments plus femoral head necrosis, who underwent prosthetic hip replacement with no post-surgical complications one year after HSCT, with a sustained response.

[Ureteral lithiasis caused by Indinavir]

We report a 27 years old male, treated with Indinavir as a prophylactic anti-HIV agent, who consulted for left ureteral pain. Intravenous and retrograde pyelograms disclosed a radioluscent stone, that was removed surgically. The physical-chemical study of the stone, demonstrated indinavir sulphate crystals.

Association of NRAMP1 promoter gene polymorphism with the susceptibility and radiological severity of rheumatoid arthritis

The natural resistant-associated macrophage protein 1 (NRAMP1) has been proposed as a candidate gene for the susceptibility to autoimmune diseases. In this study, the possible role of the functional polymorphism located at the promoter region of NRAMP1 gene in the susceptibility and clinical outcome of rheumatoid arthritis (RA) was investigated. A total of 141 Spanish RA patients and 194 controls previously typed for HLA-DRB1* were genotyped for the NRAMP1 polymorphism. No significant differences in the distribution of frequencies among RA patients and controls were observed. Nevertheless, when patients and controls were stratified according to their HLA shared epitope (SE) status, an increase of 2/2 genotype among SE-negative (SE-) patients with respect to SE- controls was observed (23% vs 7%, OR = 3.74, 95% CI 1.31-10.72). In addition, the possible role of this polymorphism in the clinical course of RA was investigated in a subgroup of 82 patients who were prospectively followed during a mean of 9 years. After follow-up, an increase of patients with the homozygous 2/2 genotype was detected among those with severe small joint radiological involvement: 73% of patients 2/2 had a severe form in contrast to 37% of patients with the genotype 2/3 and 30% of patients bearing 3/3 OR = 5.45, 95% CI 1.14-34.24). In conclusion, NRAMP1 gene promoter polymorphism could influence the radiological severity of rheumatoid arthritis and disease susceptibility, particularly in individuals lacking HLA-linked risk factors.

Molecular epidemiology of a multiresistant Pseudomonas aeruginosa outbreak in a paediatric intensive care unit

After isolation of multiresistant (MR) Pseudomonas aeruginosa from 3 hospitalized patients in a paediatric intensive care unit (PICU), a prospective surveillance programme was established to detect infected and/or colonized patients in the hospital. Isolates were examined by means of outer membrane protein (OMP) profiles, serotyping and DNA genomic analysis using pulsed-field gel electrophoresis (PFGE). Fifty-five P. aeruginosa strains were isolated from 23 hospitalized patients during September and October 1997. The median hospital stay before isolation of P. aeruginosa was 8 d. PFGE demonstrated that the same clone infected 14 patients, 4 of whom were not hospitalized in the PICU. Susceptibility patterns and OMP profiles correlated with PFGE results in 37.8% and 36.4% of cases, respectively. Serotype O11 correlated with pattern A in 77% of cases and serotype O4 correlated with unrelated strains in 75% of cases but did not discriminate between outbreak and unrelated isolates. Extensive investigation of cultures failed to identify a reservoir of P. aeruginosa. PFGE was superior to OMP analysis and serotyping for discriminating between strains. The possible mode of acquisition for most of the patients infected with the same clone was cross-contamination.

Association of the CTLA4 3' untranslated region polymorphism with the susceptibility to rheumatoid arthritis

Cytotoxic T-lymphocyte antigen 4 (CTLA4) gene polymorphism located in the 3' untranslated region (UTR) was investigated in 141 Spanish patients (38 men and 103 women) with rheumatoid arthritis (RA) and in 194 ethnically-matched healthy controls. Twenty alleles having different numbers of (AT) repeats (from 7 to 32) were found in this population. (AT)7 and (AT)16 were the most frequent alleles, and accounted for almost two-thirds of the allelic frequency in the control population. Consequently, alleles were assigned as L (large: 16 or more AT repeats) or S (short: less than 16 AT repeats). When the L/S distribution in patients and controls were compared, an increase of L alleles was observed among patients (49.9% vs. 39.7%; p = 0.02; p(c) = 0.04, odds ratio [OR] = 1.46; 95% confidence interval [CI], 1.06-2.01). Hence, the frequency of S alleles was decreased among patients (51.1% vs. 60.3%; p = 0.02; p(c) = 0.04; OR = 0.69; 95%CI, 0.50-0.95). Moreover, a statistically significant decrease in the frequency of S/S individuals was observed among RA patients (27.7% versus 40.7%; p = 0.01; p(c) = 0.03; OR = 0.56; 95%CI, 0.34-0.91). These differences were irrespective of the HLA "shared epitope" (SE) status, and were observed similarly among SE+ as well as among SE- patients. After combining these data with other reported previously by us, from studies of CTLA4 49 (A/G) and -318 (C/T) polymorphisms, we conclude that the strongest association between CTLA4 gene polymorphisms and RA susceptibility occurs with the 3' UTR polymorphism.

[Docosahexaenoic acid (DHA) in fetal development and in infant nutrition]

Docosahexanoic acid (C22:6, DHA) is a highly unsaturated omega-3 fatty acid that forms part of the central nervous and visual system structures. DHA is synthesized from its precursor, alfa-linolenic acid, that is also a omega-3 fatty acid and can be obtained from vegetable oils. Marine organisms, specially fish, are good nutritional sources of DHA and eicosapentanoic acid (EPA), another omega-3 fatty acid that has a role in vascular homeostasis. DHA increases membrane fluidity, improving neurogenesis, synaptogenesis and the activity of retinal photoreceptors. The fetus, specially during the last trimester of pregnancy, has high DHA requirements. It is provided by the mother, since fetal DHA synthesis is negligible in this stage of development. Breast feeding provides DHA to the child, but most replacement artificial formulas do not provide this fatty acid. At the present moment, many products for infant nutrition contain DHA.

Differences in morphological age-related dental changes depending on postmortem interval

Morphological methods for age estimation from teeth have been developed and applied to samples without taking the postmortem interval into consideration. We studied differences in morphological age-related changes between fresh extracted teeth and teeth from human skeletal remains in order to develop appropriate dental age estimation methods according to the time after death. Forty-three permanent teeth from dental patients were compared to 37 teeth obtained from human skeletal remains with a postmortem interval from 21 to 37 years. Morphological age-related changes were investigated by measuring variables on intact and half-sectioned teeth. A new computer assisted image analysis procedure to avoid subjectivity was developed to measure variables in sectioned specimens. Dental color, translucency length, attrition, cementum apposition, and secondary dentin showed higher values in teeth from human skeletal remains than in fresh extracted teeth. Variables obtained by morphometric analysis of computer-generated images (tooth length, tooth width, root length, and root area) showed higher values in fresh extracted teeth than in teeth from skeletal remains. The postmortem interval affects age-related morphological changes, and therefore different methods should be used for teeth of unknown postmortem interval.

The application of dental methods of identification to human burn victims in a mass disaster

This paper deals with the usefulness of dental identification in the case of 28 human burn victims of a bus accident in Spain. Postmortem forensic procedures for identification were used including general external examination, routine photographs and radiographs and complementary biological methods. Dental identification was also used and a description of the method is presented. Dental identification was established in 57% of the cases. When victims were less than 20 years of age, the success rate of identification by dental methods was higher (76% of victims in this age group). The assessment of dental age allowed the establishment of identity of four victims. We recommend that dental procedures be used in human identification after mass disasters. Odontological and radiographic procedures are powerful methods when dealing with burn victims.

Association of vitamin D receptor genotypes with early onset rheumatoid arthritis

The presence of certain vitamin D receptor (VDR) genotypes has been associated with low bone mineral density (BMD) in elderly populations as well as with accelerated bone loss in patients with rheumatoid arthritis (RA). In the present study, VDR genotypes from 120 Spanish patients with RA were investigated. Three VDR gene polymorphisms (BsmI, ApaI and TaqI) were investigated using polymerase chain reaction followed by enzymatic digestion. The distributions of VDR allelic frequencies were similar in patients and controls and therefore no influence of VDR polymorphisms on rheumatoid arthritis susceptibility could be demonstrated. However, in an analysis of the clinical features of the different VDR-related genetic subgroups, the BB/tt genotype, defined by the BsmI and TaqI restriction site polymorphisms, was identified to be weakly associated with an early onset RA in female patients. This VDR genotype has been associated with a low BMD level in various studies. When patients were stratified according to the presence of the shared HLA epitope SE, it was found that SE + female patients bearing the BB/tt genotype showed the earliest disease onset. The mechanisms by which the VDR polymorphism is associated with RA is unknown, but they could be related to the immunoregulatory properties of vitamin D.

Trans fatty acid isomers in human health and in the food industry

Trans fatty acids are unsaturated fatty acids with at least one double bond in the trans configuration. These fatty acids occur naturally in dairy and other natural fats and in some plants. However, industrial hydrogenation of vegetable or marine oils is largely the main source of trans fatty acids in our diet. The metabolic effect of trans isomers are today a matter of controversy generating diverse extreme positions in light of biochemical, nutritional, and epidemiological studies. Trans fatty acids also have been implicated in the etiology of various metabolic and functional disorders, but the main concern about its health effects arose because the structural similarity of these isomers to saturated fatty acids, the lack of specific metabolic functions, and its competition with essential fatty acids. The ingestion of trans fatty acids increases low density lipoprotein (LDL) to a degree similar to that of saturated fats, but it also reduces high density lipoproteins (HDL), therefore trans isomers are considered more atherogenic than saturated fatty acids. Trans isomers increase lipoprotein(a), a non-dietary-related risk of atherogenesis, to levels higher than the corresponding chain-length saturated fatty acid. There is little evidence that trans fatty acids are related to cancer risk at any of the major cancer sites. Considerable improvement has been obtained with respect to the metabolic effect of trans fatty acids due the development of analytical procedures to evaluate the different isomers in both biological and food samples. The oleochemical food industries have developed several strategies to reduce the trans content of hydrogenated oils, and now margarine and other hydrogenated-derived products containing low trans or virtually zero trans are available and can be obtained in the retail market. The present review provides an outline of the present status of trans fatty acids including origin, analytical procedures, estimated ingestion, metabolic effects, efforts to reduce trans isomers in our diet, and considerations for future prospects on trans isomers.

A new spontaneous mouse mutation in the Kcne1 gene

A new mouse mutant, punk rocker (allele symbol Kcne1(pkr)), arose spontaneously on a C57BL/10J inbred strain background and is characterized by a distinctive head-tossing, circling, and ataxic phenotype. It is also profoundly and bilaterally deaf. The mutation resides in the Kcne1 gene on Chromosome (Chr) 16 and has been identified as a single base change within the coding region of the third exon. The C to T nucleotide substitution causes an arginine to be altered to a termination codon at amino acid position 67, and predictably this will result in a significantly truncated protein product. The Kcne1(pkr) mutant represents the first spontaneous mouse model for the human disorder, Jervell and Lange-Nielsen syndrome, associated with mutations in the homologous KCNE1 gene on human Chr 21.

The matrix metalloproteinase gelatinase A in human dentine

A dentine protein extraction protocol was modified in order to identify matrix metalloproteinase gelatinolytic activities in the non-mineralized and mineralized phases of human dentine. Dentine proteins from 24 individual permanent molars from patients aged 15-73 years were sequentially extracted, first with guanidinium chloride (G1 extract), then EDTA (E extract), and after this demineralization step, again by guanidinium chloride (G2 extract) to dissociate collagen-associated proteins. Extracts were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and the gels were processed by Western blotting and zymography to detect gelatinolytic activities. Active and latent forms of gelatinase A were identified in the non-mineralized dentine fraction (G1 extract) of 58% of the teeth. Other gelatinolytic species were also detected by zymography with apparent M(r) of 92, 54 and 30 kDa. Although gelatinase A was detected in the G1 extracts of teeth from all ages, indicating more recent synthesis and remodelling of the predentine, gelatinase A was never detected in any E extract or in the G2 extracts of patients older than 41 years. The presence of the active form of gelatinase A in mineralized human dentine implicates this enzyme in dentine mineralization.