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2.
Int J Oral Maxillofac Surg ; 51(6): 823-831, 2022 Jun.
Article in English | MEDLINE | ID: mdl-34742634

ABSTRACT

The aim of this systematic review and meta-analysis was to determine the prevalence and characteristics of maxillary sinus septa using cone beam computed tomography and computed tomography data. Publications were searched until October 5, 2020 in three electronic databases. Additionally, article bibliographies were searched, and authors were contacted if required. This review has been registered in PROSPERO (CRD42019124933). Two independent evaluators assessed methodological quality using the Joanna Briggs Institute levels of evidence; inter-rater reliability tests were performed (Cohen's κ). The prevalence of maxillary sinus septa was expressed as a proportion; differences according to sex were reported in terms of the odds ratio (OR) and 95% confidence interval (95% CI). Heterogeneity and sources of heterogeneity were evaluated by meta-regression. Publication bias was assessed by visual analysis of the funnel plot. Statistical significance was set at P < 0.05. The 62 studies identified and included in the review involved 13,701 patients (22,460 sinuses). The meta-analysis of 35 studies (14,664 sinuses) revealed an overall mean sinus septa prevalence per sinus of 33.2% (95% CI 27.8-38.5%; I2 = 98.32%). The meta-analysis of 42 studies (9631 patients) found an overall mean sinus septa prevalence per patient of 41.0% (95% CI 36.0-46.0%, I2 = 96.45%). The OR for the difference in septa prevalence between sexes was 0.785 (95% CI 0.590-1.046; P = 0.098, I2 = 73.24%). Septa were most frequent in the middle area of the sinus and with a transverse orientation (86.0%). Within the limitations, the results suggest a high proportion of septa in the sinus, commonly in the middle area, which can interfere with the success of sinus floor elevation required for implant rehabilitation.


Subject(s)
Maxillary Sinus , Sinus Floor Augmentation , Cone-Beam Computed Tomography/methods , Humans , Maxillary Sinus/diagnostic imaging , Prevalence , Reproducibility of Results
3.
Microbiology (Reading) ; 167(12)2021 12.
Article in English | MEDLINE | ID: mdl-34914577

ABSTRACT

Members of Shewanella are ubiquitous in aquatic environments, some of which have been implicated in human infections. The progenitors of antibiotic resistance genes with clinical relevance, such as qnrA genes, have been identified in Shewanella. qnrA code for a pentapeptide repeat protein that protects type II topoisomerases, decreasing susceptibility to quinolones and fluoroquinolones. In this study, 248 genomes of 49 Shewanella species were analysed as well as 33 environmental isolates belonging to 10 Shewanella species. The presence of the qnrA gene was detected in 22.9% of the genomes and 15.2% of the isolates. The gene was more often detected in Shewanella algae, but was also detected in Shewanella carassii, Shewanella chilikensis, Shewanella haliotis and Shewanella indica. The identified genes encoded the previously described variants QnrA3 (in 22 genomes of one species), QnrA2 (eight genomes and three species), QnrA1 (six genomes and two species), QnrA7 (five genomes and two species), QnrA10 (two genomes of one species) and QnrA4 (one genome). In addition, 11 novel variants with 3 to 7 amino acid substitutions were identified (in 13 genomes and one environmental isolate). The presence of this gene appears to be species-specific although within some species several variants were detected. The study presents a previously unknown diversity of qnrA in Shewanella, highlighting the role of this genus as progenitor and reservoir of these genes. Further studies are needed to determine the phenotypes conferred by the new variants and the mechanisms that may mediate the transfer of these genes to new hosts.


Subject(s)
Quinolones , Shewanella , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/genetics , Shewanella/genetics
4.
Ecotoxicol Environ Saf ; 206: 111405, 2020 Dec 15.
Article in English | MEDLINE | ID: mdl-33010592

ABSTRACT

Soils might be a final sink for Ag2S nanoparticles (NPs). Still, there are limited data on their effects on soil bacterial communities (SBC). To bridge this gap, we investigated the effects of Ag2S NPs (10 mg kg-1 soil) on the structure and function of SBC in a terrestrial indoor mesocosm, using a multi-species design. During 28 days of exposure, the SBC function-related parameters were analysed in terms of enzymatic activity, community level physiological profile, culture of functional bacterial groups [phosphorous-solubilizing bacteria (P-SB) and heterotrophic bacteria (HB)], and SBC structure was analysed by 16S rRNA gene-targeted denaturing gradient gel electrophoresis. The SBC exposed to Ag2S NPs showed a significative decrease of functional parameters, such as ß-glucosidase activity and L-arginine consumption, and increase of the acid phosphatase activity. At the structural level, significantly lower richness and diversity were detected, but at later exposure times compared to the AgNO3 treatment, likely because of a low dissolution rate of Ag2S NPs. In fact, stronger effects were observed in soils spiked with AgNO3, in both functional and structural parameters. Changes in SBC structure seem to negatively correlate with parameters related to phosphorous (acid phosphatase activity) and carbon cycling (abundance of HB, P-SB, and ß-glucosidase activity). Our results indicate a significant effect of Ag2S NPs on SBC, specifically on parameters related to carbon and phosphorous cycling, at doses as low as 10 mg kg-1 soil. These effects were only observed after 28 days, highlighting the importance of long-term exposure experiments for slowly dissolving NPs.


Subject(s)
Metal Nanoparticles/toxicity , Microbiota/drug effects , Silver Compounds/toxicity , Soil Microbiology , Soil Pollutants/toxicity , Soil/chemistry , Acid Phosphatase/analysis , Microbiota/genetics , Oxidoreductases/analysis , RNA, Ribosomal, 16S , Soil Pollutants/analysis , beta-Glucosidase/analysis
5.
Environ Pollut ; 220(Pt A): 644-649, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27769773

ABSTRACT

Oxytetracycline (OTC) is one of the most used antibiotics in aquaculture. The main concern related to its use is the bacterial resistance, when ineffective treatments are applied for its removal or inactivation. OTC photo-degradation has been suggested as an efficient complementary process to conventional methods used in intensive fish production (e.g.: ozonation). Despite this, and knowing that the complete mineralization of OTC is difficult, few studies have examined the antibacterial activity of OTC photoproducts. Thus, the main aim of this work is to assess whether the OTC photoproducts retain the antibacterial activity of its parent compound (OTC) after its irradiation, using simulated sunlight. For that, three Gram-negative bacteria (Escherichia coli, Vibrio sp. and Aeromonas sp.) and different synthetic and natural aqueous matrices (phosphate buffered solutions at different salinities, 0 and 21‰, and three different samples from marine aquaculture industries) were tested. The microbiological assays were made using the well-diffusion method before and after OTC has been exposed to sunlight. The results revealed a clear effect of simulated sunlight, resulting on the decrease or elimination of the antibacterial activity for all strains and in all aqueous matrices due to OTC photo-degradation. For E. coli, it was also observed that the antibacterial activity of OTC is lower in the presence of sea-salts, as demonstrated by comparison of halos in aqueous matrices containing or not sea-salts.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Aquaculture , Oxytetracycline/chemistry , Oxytetracycline/pharmacology , Photolysis/radiation effects , Sunlight , Water/chemistry , Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/radiation effects , Aquaculture/methods , Hydrogen-Ion Concentration , Microbial Sensitivity Tests , Oxytetracycline/analysis , Oxytetracycline/radiation effects , Portugal , Salinity , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/pharmacology , Water Pollutants, Chemical/radiation effects
6.
Scand J Med Sci Sports ; 26(11): 1360-1372, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27152850

ABSTRACT

Experimental studies have reported that aerobic exercise after asthma induction reduces lung inflammation and remodeling. Nevertheless, no experimental study has analyzed whether regular/moderate aerobic training before the induction of allergic asthma may prevent these inflammatory and remodeling processes. For this purpose, BALB/c mice (n = 96) were assigned into non-trained and trained groups. Trained animals ran on a motorized treadmill at moderate intensity, 30 min/day, 3 times/week, for 8 weeks, and were further randomized into subgroups to undergo ovalbumin sensitization and challenge or receive saline using the same protocol. Aerobic training continued until the last challenge. Twenty-four hours after challenge, compared to non-trained animals, trained mice exhibited: (a) increased systolic output and left ventricular mass on echocardiography; (b) improved lung mechanics; (c) decreased smooth muscle actin expression and collagen fiber content in airways and lung parenchyma; (d) decreased transforming growth factor (TGF)-ß levels in bronchoalveolar lavage fluid (BALF) and blood; (e) increased interferon (IFN)-γ in BALF and interleukin (IL)-10 in blood; and (f) decreased IL-4 and IL-13 in BALF. In conclusion, regular/moderate aerobic training prior to allergic asthma induction reduced inflammation and remodeling, perhaps through increased IL-10 and IFN-γ in tandem with decreased Th2 cytokines.


Subject(s)
Airway Remodeling , Asthma/immunology , Cytokines/immunology , Lung/immunology , Physical Conditioning, Animal , Animals , Asthma/chemically induced , Bronchoalveolar Lavage Fluid/immunology , Immunohistochemistry , Inflammation , Interferon-gamma/immunology , Interleukin-10/immunology , Interleukin-13/immunology , Interleukin-4/immunology , Lung/pathology , Lung/ultrastructure , Male , Mice , Mice, Inbred BALB C , Microscopy, Electron, Transmission , Ovalbumin/adverse effects , Pneumonia/chemically induced , Pneumonia/immunology , Pneumonia/pathology , Transforming Growth Factor beta/immunology
7.
Respir Physiol Neurobiol ; 205: 1-6, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-25246186

ABSTRACT

We investigated the effects of acute hypercapnic acidosis and buffered hypercapnia on lung inflammation and apoptosis in experimental acute lung injury (ALI). Twenty-four hours after paraquat injection, 28 Wistar rats were randomized into four groups (n=7/group): (1) normocapnia (NC, PaCO2=35-45 mmHg), ventilated with 0.03%CO2+21%O2+balancedN2; (2) hypercapnic acidosis (HC, PaCO2=60-70 mmHg), ventilated with 5%CO2+21%O2+balancedN2; and (3) buffered hypercapnic acidosis (BHC), ventilated with 5%CO2+21%O2+balancedN2 and treated with sodium bicarbonate (8.4%). The remaining seven animals were not mechanically ventilated (NV). The mRNA expression of interleukin (IL)-6 (p=0.003), IL-1ß (p<0.001), and type III procollagen (PCIII) (p=0.001) in lung tissue was more reduced in the HC group in comparison with NC, with no significant differences between HC and BHC. Lung and kidney cell apoptosis was reduced in HC and BHC in comparison with NC and NV. In conclusion, in this experimental ALI model, hypercapnia, regardless of acidosis, reduced lung inflammation and lung and kidney cell apoptosis.


Subject(s)
Acidosis , Acute Lung Injury/physiopathology , Apoptosis , Hypercapnia , Pneumonia/physiopathology , Acute Disease , Animals , Buffers , Disease Models, Animal , Hydrogen-Ion Concentration , In Situ Nick-End Labeling , Rats , Rats, Wistar , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction
8.
Mar Pollut Bull ; 64(2): 263-71, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22177286

ABSTRACT

We compare the environmental characteristics and bacterial communities associated with two rushes, Juncus maritimus and Bolboschoenus maritimus, and adjacent unvegetated habitat in a salt marsh subjected to historical mercury pollution. Mercury content was higher in vegetated than unvegetated habitat and increased with sampling depth. There was also a significant relationship between mercury concentration and bacterial composition. Habitat (Juncus, Bolboschoenus or unvegetated), sample depth, and the interaction between both, however, explained most of the variation in composition (~70%). Variation in composition with depth was most prominent for the unvegetated habitat, followed by Juncus, but more constrained for Bolboschoenus habitat. This constraint may be indicative of a strong plant-microbe ecophysiological adaptation. Vegetated habitat contained distinct bacterial communities associated with higher potential activity of aminopeptidase, ß-glucosidase and arylsulphatase and incorporation rates of (14)C-glucose and (14)C-acetate. Communities in unvegetated habitat were, in contrast, associated with both higher pH and proportion of sulphate reducing bacteria.


Subject(s)
Bacterial Physiological Phenomena/drug effects , Cyperaceae/physiology , Magnoliopsida/physiology , Mercury/toxicity , Plant Physiological Phenomena , Water Pollutants, Chemical/toxicity , Wetlands , Bacteria/classification , Bacteria/genetics , Ecosystem , Geologic Sediments/chemistry , Geologic Sediments/microbiology , Hydrogen-Ion Concentration , Mercury/analysis , RNA, Ribosomal, 16S , Time Factors , Water Pollutants, Chemical/analysis
9.
Plasmid ; 67(3): 252-8, 2012 May.
Article in English | MEDLINE | ID: mdl-22107909

ABSTRACT

In this work the presence of broad-host-plasmids in an estuary in Portugal has been investigated. Pseudomonas putida KT2442 was used as model recipient bacteria in biparental matings with tetracycline and mercury to select for resistance phenotypes. As a result, 7 transconjugants were shown to carry broad-host-plasmids from the IncP-1 group, as seen by PCR amplification of the trfA gene. Sequence analysis confirmed the isolation of 4 plasmids from ß-1 subgroup and 3 assigned to the recently described ε subgroup. To our knowledge this is the first report concerning the detection and isolation of IncP-1ß and ε plasmids in estuarine waters. Moreover it is shown that, even though the retrieved plasmids are phylogenetically close to previously characterized plasmids, such as pB10 and pKJK5, respectively, they constitute new molecular variants.


Subject(s)
Plasmids/genetics , Plasmids/isolation & purification , Water Microbiology , Water/chemistry , Amino Acid Sequence , DNA, Bacterial , Drug Resistance, Bacterial , Escherichia coli/genetics , Escherichia coli/isolation & purification , Mercury/metabolism , Molecular Sequence Data , Phylogeny , Portugal , Pseudomonas putida/genetics , Pseudomonas putida/isolation & purification , Pseudomonas putida/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Sequence Analysis, DNA , Tetracycline/metabolism
10.
Lett Appl Microbiol ; 52(4): 360-6, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21255057

ABSTRACT

AIMS: To assess the variability in UV-B (280-320 nm) sensitivity of selected bacterial isolates from the surface microlayer and underlying water of the Ria de Aveiro (Portugal) estuary and their ability to recover from previous UV-induced stress. METHODS AND RESULTS: Bacterial suspensions were exposed to UV-B radiation (3·3 W m⁻²). Effects on culturability and activity were assessed from colony counts and (3) H-leucine incorporation rates, respectively. Among the tested isolates, wide variability in UV-B-induced inhibition of culturability (37·4-99·3%) and activity (36·0-98·0%) was observed. Incubation of UV-B-irradiated suspensions under reactivating regimes (UV-A, 3·65 W m⁻²; photosynthetic active radiation, 40 W m⁻²; dark) also revealed diversity in the extent of recovery from UV-B stress. Trends of enhanced resistance of culturability (up to 15·0%) and enhanced recovery in activity (up to 52·0%) were observed in bacterioneuston isolates. CONCLUSIONS: Bacterioneuston isolates were less sensitive and recovered more rapidly from UV-B stress than bacterioplankton isolates, showing enhanced reduction in their metabolism during the irradiation period and decreased culturability during the recovery process compared to bacterioplankton. SIGNIFICANCE AND IMPACT OF THE STUDY: UV exposure can affect the diversity and activity of microbial communities by selecting UV-resistant strains and alter their metabolic activity towards protective strategies.


Subject(s)
Bacteria/radiation effects , Plankton/radiation effects , Ultraviolet Rays , Water Microbiology , Bacteria/isolation & purification , Plankton/isolation & purification , Portugal , Seawater/microbiology
11.
J Appl Microbiol ; 108(2): 611-23, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19659697

ABSTRACT

AIMS: Aeromonas is ubiquitous in aquatic environments and may cause infectious diseases in fish and humans. However, reliable and specific methods to evaluate the diversity and dynamics of Aeromonas populations are currently unavailable. This study aimed to develop PCR-DGGE methodologies for culture-independent analysis of Aeromonas populations in water systems. METHODS AND RESULTS: Three primer sets were designed to amplify selected sections of genes gyrB, rpoD and sodB from Aeromonas. Their specificity was confirmed by in silico analysis and by PCR on DNA from pure cultures. Estuarine water samples were analyzed by PCR-DGGE using those primers. DGGE patterns clearly clustered according to seasonal factors, and Aeromonas communities were surprisingly stable along a salinity gradient. Sequences of cloned amplicons affiliated to sequences belonging to seven Aeromonas species previously isolated from the same environment. CONCLUSIONS: The three systems used showed to be useful to describe the diversity of Aeromonas communities. However, the combined use of more than one primer set is advisable. SIGNIFICANCE AND IMPACT OF THE STUDY: The methods presented here can be applied to understand the natural pool of Aeromonas and also to monitor and control these bacteria in aquatic reservoirs.


Subject(s)
Aeromonas/genetics , Electrophoresis, Gel, Two-Dimensional/methods , Polymerase Chain Reaction/methods , Water Microbiology , Base Sequence , Cluster Analysis , DNA Primers , DNA, Bacterial/genetics , Genes, Bacterial , Genetic Variation , Humans , Phylogeny , Portugal , Seasons
12.
J Appl Microbiol ; 105(6): 2187-94, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19120664

ABSTRACT

AIMS: This study evaluates the microbial ecology of 'Alheira' by traditional microbiological analysis and a PCR-denaturing gradient gel electrophoresis (DGGE) protocol. METHODS AND RESULTS: Total microbial DNA from 'Alheiras' was extracted directly from the products and subjected to PCR using Eubacterial primers for 16S rDNA. The amplicons were separated by DGGE. The results demonstrated that different products of the same batch display identical profiles, whereas products from different batches of the same producer could display different DGGE profiles. 'Alheiras' from different producers were distinguishable based on the respective DGGE profiles. The obtained sequences from prevalent phylotypes affiliated with order Lactobacillales and order Bacillales and class Gammaproteobacteria. The same samples were subjected to traditional microbiological analysis. In both methods, lactic acid bacteria were dominant and were present together with other organisms, mainly members of the family Micrococcaceae. CONCLUSIONS: The approach explored in this study allowed the description of the microbial community present in 'Alheira' in particular the diversity of lactic acid bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: This can be useful for the microbiological characterization of traditional products in order to develop new methods of quality control capable of supporting a standardization of the processes, while preserving their typical traits.


Subject(s)
Bacteria/isolation & purification , DNA, Bacterial/analysis , Food Microbiology , Meat Products/microbiology , Polymerase Chain Reaction/methods , Bacteria/classification , Bacteria/genetics , Bacteriological Techniques , DNA Primers/genetics , Fermentation , Lactobacillus/genetics , Molecular Sequence Data , Portugal , RNA, Ribosomal, 16S/analysis
13.
Lett Appl Microbiol ; 47(6): 526-33, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19120920

ABSTRACT

AIMS: To investigate the diversity and dissemination of tetracycline resistance genes in isolates from estuarine waters. METHODS AND RESULTS: Forty-two out of 164 multi-resistant isolates previously obtained were resistant or less-susceptible to tetracycline, as evaluated by the disc diffusion method. Minimal inhibitory concentration for resistant bacteria ranged from 16 to 256 mg l(-1). Screening of tet genes by polymerase chain reaction showed that 88% of the isolates carried at least one of the genes tested, namely tet(A) (present in 13 isolates), tet(B) (present in 13 isolates), tet(C) (present in 3 isolates), tet(D) (present in 1 isolate), tet(E) (present in 6 isolates) and tet(M) (present in 1 isolate). One isolate carried tet(A) and tet(M). To our knowledge, this study presents the first description of a tet(D) gene in Morganella morganii. Hybridization revealed that tet genes were plasmid-located in 31% of the isolates. Those isolates were included as donors in conjugation experiments and 38% transferred tetracycline resistance. CONCLUSIONS: A considerable diversity of tet genes was detected in the estuary. Frequently, these genes were associated with plasmids and could be transferred to Escherichia coli. SIGNIFICANCE AND IMPACT OF THE STUDY: The results presented provide further evidence of the role played by estuarine reservoirs in antibiotic resistance maintenance and dissemination.


Subject(s)
Bacterial Proteins/genetics , Gram-Negative Bacteria/genetics , Tetracycline Resistance , Water Microbiology , Bacterial Proteins/metabolism , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/isolation & purification , Microbial Sensitivity Tests , Molecular Sequence Data , Tetracyclines/pharmacology
14.
Eur J Gynaecol Oncol ; 28(6): 447-50, 2007.
Article in English | MEDLINE | ID: mdl-18179134

ABSTRACT

UNLABELLED: Primary chemotherapy is increasingly used in patients with large operable breast cancer. Docetaxel and epirubicin are the most active agents in breast cancer treatment. PURPOSE: To evaluate clinical response rate, breast conserving surgery and pathological response rate in patients with large operable breast cancer treated with docetaxel followed by docetaxel and epirubicin as primary chemotherapy. PATIENTS AND METHODS: Patients with operable breast cancer more than 3 cm in the longest diameter with T2N0, T2N1 and T3N0 disease were enrolled. Patients were treated with three cycles of docetaxel 100 mg/m2 followed by three cycles of docetaxel 75 mg/m2 and epirubicin 90 mg/m2 prior to surgery. RESULTS: Sixty-five patients were enrolled between 09/2002 and 12/2005. The median age was 48.9 years and 72.3% were premenopausal. Median tumour size was 4.26 cm, 10.8% were T3 tumours and 38.5% had clinical positive lymph nodes. Of the tumours 58.5% were grade 1/2, 33.9% ER positive and 21.5% c-erb negative. All six cycles were administered to 62 patients; six cycles were delayed and five had dose reductions. Complete clinical response occurred in 41.5% of patients and partial response in 49.2%. Breast conserving surgery was performed in 30% of patients however it was feasible in 57%. Complete pathological response occurred in both primary tumour and nodes in 28%, and in 34% just in the primary tumour. Nine percent of cases had neutropenia and 7.7% febrile neutropenia, and two cases had a hypersensitivity reaction to docetaxel. One associated treatment death occurred. CONCLUSION: Docetaxel followed by epirubicin and docetaxel as primary chemotherapy results in a high clinical and pathological response rate. The majority of adverse events were predictable and manageable.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Adult , Breast Neoplasms/surgery , Combined Modality Therapy , Docetaxel , Drug Administration Schedule , Epirubicin/administration & dosage , Female , Humans , Middle Aged , Taxoids/administration & dosage
15.
Appl Microbiol Biotechnol ; 71(4): 555-62, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16240116

ABSTRACT

An up-flow fixed bed reactor (UFBR) was established to investigate the biodegradation of fluorobenzene (FB) under a number of operating conditions, which included variation in the concentration of FB in the feed stream (up to 180 mg l(-1)) and temporary suspension of feeding. Degradation of FB was followed for a period of 8 months under a continuous flow regime. During the operation of the UFBR, FB was never detected in the reactor effluent, being biodegraded by the microbial biofilm or adsorbed to the granular activated carbon (GAC). Biodegradation of FB was observed from the beginning of the reactor operation, and overall, it accounted for 50% of the total amount fed to the bioreactor. High organic loads of FB (210-260 mg d(-1) dm(-3)) were found to affect the biological removal efficiency, possibly due to an inhibitory effect caused by the higher FB concentrations fed to the bioreactor (149-179 mg l(-1)). When FB feeding was suspended for 1 month, biodegradation continued, indicating that the adsorbed FB became bioavailable. Biofilm bacterial dynamics were followed throughout the UFBR operation by denaturing gradient gel electrophoresis and plate-counting techniques, showing that a quite stable community was found in the bioreactor, and this was mainly attributed to the high selective pressure exerted by the presence of FB.


Subject(s)
Biofilms , Bioreactors/microbiology , Fluorobenzenes/metabolism , Water Pollutants, Chemical/metabolism , Biomass , Charcoal , Cluster Analysis , Colony Count, Microbial , Electrophoresis, Polyacrylamide Gel , Solvents
16.
Biotechnol Bioeng ; 85(6): 683-94, 2004 Mar 20.
Article in English | MEDLINE | ID: mdl-14966810

ABSTRACT

Conventional aerobic nitrification was adversely affected by single pulse inputs of six different classes of industrially relevant chemical toxins: an electrophilic solvent (1-chloro-2,4-dinitrobenzene, CDNB), a heavy metal (cadmium), a hydrophobic chemical (1-octanol), an uncoupling agent (2,4-dinitrophenol, DNP), alkaline pH, and cyanide in its weak metal complexed form. The concentrations of each chemical source that caused 1 5, 25, and 50% respiratory inhibition of a nitrifying mixed liquor during a short-term assay were used to shock sequencing batch reactors containing nitrifying conventional activated sludge. The reactors were monitored for recovery over a period of 30 days or less. All shock conditions inhibited nitrification, but to different degrees. The nitrate generation rate (NGR) of the shocked reactors recovered overtime to control reactor levels and showed that it was a more sensitive indicator of nitrification inhibition than both initial respirometric tests conducted on unexposed biomass and effluent nitrogen species analyses. CDNB had the most severe impact on nitrification, followed by alkaline pH 11, cadmium, cyanide, octanol, and DNP. Based on effluent data, cadmium and octanol primarily inhibited ammonia-oxidizing bacteria (AOB) while CDNB, pH 11,and cyanide inhibited both AOB and nitrite-oxidizing bacteria (NOB). DNP initially inhibited nitrification but quickly increased the NGR relative to the control and stimulated nitrification after several days in a manner reflective of oxidative uncoupling. The shocked mixed liquor showed trends toward recovery from inhibition for all chemicals tested, but in some cases this reversion was slow. These results contribute to our broader effort to identify relationships between chemical sources and the process effects they induce in activated sludge treatment systems.


Subject(s)
Bacteria, Aerobic/drug effects , Bacteria, Aerobic/metabolism , Nitrates/metabolism , Nitrites/metabolism , Quaternary Ammonium Compounds/metabolism , Sewage/microbiology , 1-Octanol/pharmacology , Bacteria, Aerobic/growth & development , Bioreactors/microbiology , Cadmium/pharmacology , Cyanides/pharmacology , Dinitrobenzenes/pharmacology , Dinitrochlorobenzene/pharmacology , Hydrogen-Ion Concentration , Industrial Waste/prevention & control , Water Purification/methods
17.
Water Sci Technol ; 50(10): 287-94, 2004.
Article in English | MEDLINE | ID: mdl-15656324

ABSTRACT

Toxic shock-induced deflocculation was examined for activated sludge exposed to six different classes of industrially relevant chemical toxins: an electrophilic solvent (1-chloro-2,4-dinitrobenzene, CDNB), a heavy metal (cadmium), a hydrophobic chemical (1-octanol), an uncoupling agent (2,4-dinitrophenol, DNP), alkaline pH, and weakly complexed cyanide. The concentrations required to inhibit respiration by 50% were used to shock sequencing batch reactors (SBRs) containing a nitrifying (10-day solids retention time (SRT)) and a non-nitrifying (2-day SRT) biomass. Effluent total suspended solids (TSS) and soluble potassium were monitored to examine deflocculation caused by a bacterial stress response mechanism called glutathione-gated potassium efflux (GGKE). Reactors were monitored for recovery over a period of 3 SRTs or less. At the concentrations tested, CDNB, cadmium and pH 11 were found to cause significant increases in effluent TSS concentrations and showed elevated levels of potassium. In contrast, octanol, DNP and cyanide did not induce severe deflocculation and showed moderate increases in effluent potassium levels. Recovery of effluent TSS and potassium concentrations to control levels generally did not correlate, supporting the hypothesis that reflocculation requires regrowth of biomass. These results suggest that different chemicals induce deflocculation in SBRs, but deflocculation is not necessarily caused by the GGKE mechanism in all cases.


Subject(s)
Bioreactors , Industrial Waste , Sewage , Water Pollutants, Chemical , Water Purification/methods , 1-Octanol/metabolism , 1-Octanol/toxicity , Biomass , Cadmium/metabolism , Cyanides/metabolism , Cyanides/toxicity , Dinitrobenzenes/metabolism , Dinitrobenzenes/toxicity , Flocculation , Glutathione/metabolism , Hydrogen-Ion Concentration , Nitrites/chemistry , Nitrites/metabolism , Oxygen/metabolism , Potassium/metabolism , Sewage/chemistry , Sewage/microbiology , Time Factors , Water Pollutants, Chemical/metabolism , Water Pollutants, Chemical/toxicity
18.
Prog. diagn. trat. prenat. (Ed. impr.) ; 15(3): 126-132, jul. 2003. ilus, tab, graf
Article in Pt | IBECS | ID: ibc-31746

ABSTRACT

Introducción. Las técnicas del genotipado de los grupos sanguíneos están particularmente indicadas cuando tenemos que establecer situaciones de poblaciones tras reacciones postransfusionales, tests positivos a la antiglobulina o en casos de enfermedad hemolítica del recién nacido (EHRN). Últimamente ha sido demostrado que la presencia de ADN fetal en plasma materno tiene una tasa de éxito elevada a partir del segundo trimestre de embarazo, pudiendo de esta forma ser solucionadas muchas de las dificultades técnicas existentes. Objetivo. Aplicar las tecnologías de biología molecular, concretamente PCR a tiempo real, efectuando la determinación prenatal del genotipo RHD por métodos no invasivos, utilizando muestras de plasma materno. Material y métodos. Cincuenta y cuatro muestras de plasma correspondientes a 49 embarazadas caucásicas portuguesas Rh(D) negativas con cónyuges Rh(D) positivos. En las muestras de sangre se realizó el fenotipado de los grupos sanguíneos ABO y Rh, la búsqueda de anticuerpos irregulares y el estudio genético por la técnica de PCR en tiempo real. En todos los casos fue posible obtener durante el parto una muestra de sangre del cordón umbilical. Resultados. Los resultados obtenidos a través del genotipado, utilizando plasma materno, fueron concordantes con el fenotipo de sangre del cordón en 46 casos. En 8 casos, a pesar de que en el fenotipado se diagnosticó de fetos RHD-, en el recién nacido se diagnosticaron como R(h)D positivos (en todos los casos las muestras fueron de embarazadas con gestaciones menores de 25 semanas). No hubo casos de resultados falsos-positivos. Discusión. Los resultados indican que el genotipado RHD fetal, utilizando muestras de plasma materno, son fiables a partir de la semana 24 de embarazo. A pesar de ello, son nece sarios más estudios para adoptar este tipo de metodología en la práctica clínica de rutina (AU)


Subject(s)
Pregnancy , Female , Humans , Genotype , Prenatal Diagnosis/methods , Rh-Hr Blood-Group System/analysis , Blood Group Antigens/analysis , Erythroblastosis, Fetal/diagnosis , Primed In Situ Labeling/methods , Blood Grouping and Crossmatching/methods , Fetal Blood/immunology
20.
Immunohematology ; 18(3): 59-64, 2002.
Article in English | MEDLINE | ID: mdl-15373552

ABSTRACT

The most clinically important blood group systems in transfusion medicine, excluding the ABO system, are the RH, Kell, and Kidd systems. Alloantibodies to antigens of these systems may be produced following blood transfusion or during pregnancy and can result in serious hemolytic transfusion reactions and hemolytic disease of the newborn. We developed rapid and robust techniques for RHD, RHCE, KEL, and JK genotyping with the use of a real-time polymerase chain reaction instrument. Two fluorescence-based methods for the detection of amplification products were used: for KEL1/KEL2, JK1/JK2, and RHE/RHe (exon 5) we used the hybridization probes protocol; for RHC/RHc the analysis was done in sequences of exon 1 for RHC and exon 2 for RHc; and for RHD, analysis was done in sequences of intron 4, exon 7, and exon 4 pseudogene using the SYBR Green I protocol. The genotyping tests were validated with samples from 85 Caucasian Portuguese and 15 Black European blood donors. Complete phenotype-genotype correlations were obtained. The potential use of the presented methods can be predicted in clinical transfusion medicine, allowing appropriate monitoring, early intervention, and improved care. When blood group genotyping techniques are necessary, this methodology is highly competitive for a routine laboratory.

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